Other calculators
649 calculators Beer-Lambert Law Calculator Solve A = ε·c·l for absorbance, concentration, molar absorptivity, or path length. Supports mmol/L and umol/L units, transmittance conversion, and a calibration chart.
Open Cone Volume Calculator Calculate cone volume, slant height, lateral area, half-angle and total surface area. Supports truncated cones (frustum), diameter input, and cost estimation.
Open Countdown Calculator Count down to any date or event. See years, months, weeks, days, hours, minutes, and seconds left. Includes preset holidays, countup mode, and working-days count.
Open Cylinder Volume Calculator Calculate cylinder volume, surface area, and liquid capacity in litres and gallons. Supports hollow cylinders, oblique mode, diameter input, and reverse-solve.
Open Dodecagon Calculator Calculate area, perimeter, apothem, circumradius, all 5 diagonals, and incircle/circumcircle area of a regular dodecagon. Reverse-solve from any known value.
Open Ellipse Area Calculator Find ellipse area, perimeter, eccentricity, focal distance, and latus rectum. Input semi-axes or full diameters, or reverse-solve a missing axis from the area.
Open Fahrenheit to Celsius Converter Convert Fahrenheit to Celsius, Kelvin, or Rankine instantly. Reverse mode converts any scale to any other. Full reference chart and step-by-step formula.
Open Greatest Common Factor Calculator Find the GCF of any integers by Euclidean algorithm, prime factorization, or listing factors. Shows all common factors, LCM, and full step-by-step working.
Open Heptagon Calculator Calculate every dimension of a regular heptagon: area, perimeter, apothem, circumradius, diagonals, and interior angles. Solve from side, apothem, or circumradius.
Open Kg to Lbs Converter Convert kilograms to pounds or reverse: lbs to kg. Shows decimal pounds, stones-and-pounds, ounces, and grams with full show-your-work steps.
Open Kite Area Calculator Calculate kite area by diagonals or by two sides and the included angle. Also get perimeter, incircle radius, and all kite angles, with worked steps.
Open Lbs to Kg Converter Convert pounds to kilograms instantly. Supports pounds-only or pounds-and-ounces input, reverse kg-to-lbs mode, and outputs in kg, grams, ounces, and stones.
Open Meters to Feet Converter Convert meters (or cm, mm, km) to feet instantly. Get decimal feet, feet-and-inches, fractional inches, and a full reverse mode (feet to meters).
Open Parallelogram Area Calculator Calculate parallelogram area three ways: base x height, two sides and an angle, or two diagonals and their angle. Also returns perimeter and height.
Open Power Converter Convert power across 16 units including watts, kW, MW, GW, all 4 horsepower types, BTU/hr, tons of refrigeration and kcal/hr. Instant results with step-by-step math.
Open PPM Calculator Calculate ppm, ppb, ppt, mg/L and percentage from solute and solution mass. Reverse-solve for the solute mass you need to hit any target concentration.
Open Rhombus Area Calculator Find rhombus area three ways: diagonals (d1 x d2)/2, base x height, or side squared x sin(angle). Also outputs perimeter, side, height, and both interior angles.
Open Sphere Volume Calculator Calculate sphere volume, surface area, circumference, and diameter. Solve forward or in reverse from any one known value. Hemisphere and spherical cap modes included.
Open Wage Calculator Convert any wage across 8 pay periods. Enter your rate, hours, days worked and time off to get unadjusted and vacation-adjusted figures for every period.
Open Wave Speed Calculator Calculate wave speed, frequency, wavelength, period and wavenumber. Supports general, sound-in-air, string and EM-wave modes with full unit switching.
Open 10 Sided Dice Roller (D10) Roll 1-15 ten-sided (D10) dice instantly. Get the total, average, min/max, probability breakdown, and expected value with a full probability chart.
Open 100 Amp Wire Size Calculator Find the correct wire gauge for a 100 amp circuit. Enter distance, voltage, material and temperature to get the NEC-compliant AWG size and voltage drop.
Open 100 Day Calculator Calculate the exact date 100 days from today or any start date. Choose calendar days or business days, go forward or backward, and see a full breakdown.
Open 120 Day Calculator Calculate what date falls 120 days (or any count) from a start date. Supports business days, reverse mode, day of week, week number, and day of year.
Open 16:10 Aspect Ratio Calculator Calculate 16:10 aspect ratio dimensions instantly. Solve for width or height, get diagonal size, pixel density (PPI), and display area with a step-by-step breakdown.
Open 16:9 Aspect Ratio Calculator Calculate width, height, or diagonal for any 16:9 resolution instantly. Covers HD, Full HD, 4K and custom sizes with a common-resolution reference table.
Open 20/20 Vision Calculator: Convert Eye Prescription to Visual Acuity Convert your eye prescription (sphere, cylinder) to visual acuity on four scales: 20/20 Snellen, metric 6/6, decimal, and LogMAR. Full reference table included.
Open 220 Volt Wire Size Calculator Find the right AWG wire gauge for any 220/240V circuit. Enter load current, run length, and voltage drop limit to get the NEC-compliant wire size for copper or aluminum.
Open 2D Distance Calculator Calculate the straight-line distance between two 2D points. Shows exact radical form, midpoint, slope fraction, line equation, angle, and step-by-step working.
Open 3-Phase Motor Amperage Calculator Calculate 3-phase motor full-load amperage, starting current, conductor size, and circuit breaker rating from HP or kW, voltage, efficiency, and power factor.
Open 30-Day Calculator: Add or Subtract Days with Business Day Mode Add or subtract any number of days from any start date, with a business-days-only option. Find the exact end date, day of week, weeks, and a full breakdown instantly.
Open 30 Day Calculator Find the exact date 30 calendar or business days from today or any custom start date. Supports add or subtract, shows week number, day of year, and time conversions.
Open 30 Min Calculator Free 30-minute calculator: find the time 30 min from any start, add or subtract intervals, build a daily schedule, and convert 30 min to hours, seconds, and decimal.
Open 4-Sided Dice Roller Calculator Roll one or more D4 dice online instantly. See your total, individual die results, modifier, mean, min and max, plus the full probability distribution for your roll.
Open 5K Pace Calculator Enter your 5K finish time to get your pace per km, pace per mile, and speed. Or enter a target pace to find your finish time. Includes a per-km split schedule.
Open 6 Month Calculator Add or subtract 6 months (or any number of months) from any date. Instantly see the result date, day of the week, and months between two dates.
Open 6 Sided Dice Probability Calculator Calculate the exact probability for any 6-sided dice roll: sum, at least, at most, all matching, and more. Instant results with full working shown.
Open 6-Sided Dice Roller Calculator Roll 1-10 six-sided dice and instantly see the probability of every possible sum, expected value, standard deviation, and the full probability distribution.
Open 90% Confidence Interval Calculator Calculate the 90% confidence interval for a sample mean. Enter mean, standard deviation, and sample size to get bounds, margin of error, and standard error instantly.
Open 90 Day Calculator Find the date exactly 90 days (or any number of days) from today or a custom start date. Includes business-day mode, reverse lookup, and a time breakdown.
Open 90 Minute Sleep Cycle Calculator Find your ideal bedtime or wake time using 90-minute sleep cycles. Adjust onset and cycle length, and see 4, 5, and 6-cycle options with a full schedule table.
Open 95% Confidence Interval Calculator Calculate the 95% confidence interval for a sample mean. Enter mean, standard deviation, and sample size to get bounds, margin of error, and step-by-step working.
Open 99% Confidence Interval Calculator Calculate a 99% confidence interval for a mean (z or t) or proportion with step-by-step working, margin of error, and a normal-curve visual.
Open AAA Triangle Calculator Enter all three angles of a triangle to get relative side ratios, triangle type, and (with one known side) area, perimeter, inradius, and circumradius.
Open AAS Triangle Calculator Solve any AAS triangle instantly: enter two angles and the non-included side to get all sides, area, perimeter, inradius, and circumradius with step-by-step working.
Open ABC Triangle Calculator Solve any triangle from 3 known values. Enter any mix of sides (a, b, c) and angles (A, B, C) to find all sides, angles, area, perimeter, inradius, circumradius, and heights.
Open Acceleration due to Gravity Calculator Calculate gravitational acceleration on Earth, the Moon, Mars, or any custom body. Adjust altitude, switch metric and imperial units, and see step-by-step math.
Open Acceleration, Force and Mass Calculator (F = ma) Calculate acceleration, force, or mass using Newton's second law F = ma. Choose metric or imperial units, see your working, and explore a real-world reference table.
Open Acres to Square Feet Converter Convert acres to square feet instantly. Get the result in sq ft plus square yards, square meters, hectares, and square miles, with a step-by-step breakdown.
Open Add Days Calculator Add or subtract days, weeks, months, and years from any date. Get the resulting date, day of the week, and see business-days mode. Free, instant, no sign-up.
Open Add Minutes Calculator Add or subtract minutes (and hours) from any start time and instantly see the result in 12-hour or 24-hour format, with day-crossing detection and a step-by-step breakdown.
Open Adding Hours and Minutes Calculator Add or subtract up to six time entries in hours and minutes. See the total in HH:MM, decimal hours, and days instantly, with a full step-by-step breakdown.
Open Age in Days Calculator Find out exactly how many days old you are. Enter your birthday and get your age in days, weeks, months, hours, and seconds - plus your next milestone day.
Open Age in Hours Calculator Enter your date of birth and instantly see your exact age in hours, days, weeks, minutes, and years. Accounts for leap years and shows a full time breakdown.
Open Age in Minutes Calculator Find out exactly how many minutes you have been alive. Enter your date of birth and get your age in minutes, hours, days, weeks, months, and seconds instantly.
Open Age in Months Calculator Calculate exact age in months from any birthdate. Get total months, a years-months-days breakdown, total weeks, days, and a child developmental milestone chart.
Open Age in Seconds Calculator Find out exactly how many seconds old you are with a full time breakdown: years, months, weeks, days, hours, minutes, and total seconds. Includes upcoming milestones.
Open Age in Weeks Calculator Find your exact age in weeks and days from your date of birth. See your age broken down into years, months, weeks, and days, with key life milestones.
Open Age in Years Calculator Calculate your exact age in years, months, weeks, days, hours, minutes, and seconds from your date of birth. Shows days to your next birthday and a lifetime timeline.
Open Age in Years, Months, and Days Calculator Find your exact age in years, months, and days from any birth date. Also shows total days, weeks, hours, minutes, next birthday countdown, and leap-year facts.
Open Age on Other Planets Calculator Find your age on Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto and the Moon. Instant results with the formula, worked example and milestone table.
Open Age to Birthday Calculator Enter your date of birth to get your exact age, days until your next birthday, zodiac sign, birthstone, generation, and more. Free instant results.
Open AND Probability Calculator Calculate P(A and B) for independent or dependent events instantly. See the full formula, step-by-step working, complement, union, XOR, and multi-trial probability.
Open Angle Conversion Calculator Convert any angle between degrees, radians, gradians, turns, arcminutes, arcseconds, and milliradians instantly. See the formula and step-by-step working.
Open Angle of Impact Calculator Calculate the angle of impact from bloodstain width and length using arcsin(W/L). Includes height-of-origin solve, reverse mode, and forensics reference.
Open Angle of Incidence Calculator Calculate the angle of incidence or refraction using Snell's Law. Get the critical angle, Brewster's angle, and choose from 12 preset optical media.
Open Angle of Refraction Calculator Calculate the angle of refraction using Snell's law. Instantly find the critical angle, Brewster angle, and total internal reflection with built-in material presets.
Open Angle of Right Triangle Calculator Find both acute angles of a right triangle from two sides, a side and area, or one side and an angle. Instant results with step-by-step working and a labeled diagram.
Open Angstrom to Nanometer Converter Convert angstroms to nanometers instantly. Bidirectional: enter angstroms or nm. See the formula, worked example, wavelength band table, and real-world scale reference.
Open Annual Pay Calculator Convert hourly, daily, weekly, biweekly, monthly or any pay frequency to annual salary instantly. Adjusts for overtime, holidays and vacation days.
Open Annual Salary to Hourly Wage Calculator Convert annual salary to hourly wage (and back) in seconds. See your pay across all 8 periods, with optional PTO and holiday adjustments. Free online tool.
Open Annual to Monthly Salary Calculator Convert your annual salary to monthly, biweekly, weekly, daily, and hourly pay. Enter your yearly income and hours worked to see every pay period, with an optional tax rate.
Open Aquarium Calculator Calculate aquarium volume in gallons and liters for 6 tank shapes. Get usable water volume, filled weight, heater wattage, filter GPH, and fish stocking guide.
Open Area of a Frustum of a Cone Calculator Calculate total surface area, lateral area, base areas, volume, and slant height of a conical frustum. Metric and imperial units with full step-by-step working.
Open Area of a Sphere Calculator Calculate the surface area of a sphere from radius, diameter, volume, circumference, or surface area. Shows the full formula and step-by-step working.
Open Area of a Square Calculator Calculate the area of a square from its side, diagonal, perimeter, circumradius, or inradius. Get perimeter, diagonal, and all dimensions instantly in metric or imperial.
Open Area of a Trapezoid Calculator Calculate the area, perimeter, midsegment, and height of any trapezoid. Choose metric or imperial units, see the full worked steps, and solve for any missing side.
Open Area of a Triangle SAS Calculator Calculate the area of a triangle from two sides and the included angle (SAS). Get area, perimeter, third side, heights, and all angles instantly.
Open Area of an Oblique Triangle Calculator Calculate the area of any oblique triangle using SAS, SSS (Heron's formula), AAS/ASA, or base-height. Instant results with step-by-step working shown.
Open Area of an Obtuse Triangle Calculator Calculate the area of any obtuse triangle using base and height, SAS, three sides (Heron's formula), or two angles and a side. Step-by-step breakdown included.
Open Area of Quadrilateral Calculator Calculate the area of any quadrilateral: rectangle, square, parallelogram, rhombus, trapezoid, kite, or irregular shape by coordinates or Bretschneider formula.
Open ASA Triangle Calculator Solve any ASA triangle instantly: enter two angles and the included side to get all sides, angles, area, perimeter, inradius and circumradius with step-by-step working.
Open ATM Conversion Calculator Convert atmospheres (atm) to PSI, pascals, bar, kPa, torr, mmHg, inHg, and millibar instantly. Enter any pressure unit and get all others at once.
Open ATM to Pascals Converter Convert atmospheres to pascals instantly. Two-way atm/Pa converter with bar, kPa, MPa, PSI, mmHg, and mbar outputs, step-by-step math, and a reference table.
Open Bar to ATM Conversion Calculator Convert bar to atmospheres (atm) instantly, plus kPa, Pa, psi, torr, and mbar. Formula, worked example, reference table, and bidirectional conversion.
Open Bar to PSI Conversion Calculator Convert bar to psi (or psi to bar) instantly. Includes the exact formula, a worked example, a quick-reference chart for common pressures, and reverse conversion.
Open Bar to PSIG Converter Convert bar to PSIG (gauge pressure) instantly. Formula, reverse PSIG-to-bar mode, common pressure reference table, worked examples, and real-world applications.
Open Base of a Triangle Calculator Find the base of any triangle in seconds using area and height, two sides and an angle, the perimeter, or Pythagorean theorem for right triangles.
Open Beighton Score Calculator Score all 9 Beighton hypermobility maneuvers, get an age-adjusted interpretation for GJH, a joint-by-joint breakdown, and the 5-point questionnaire in one tool.
Open Berg Balance Test Calculator Score all 14 Berg Balance Scale tasks online. Get your BBS total, fall risk category, MDC95, and a plain-English interpretation for clinical or home use.
Open Bike Cadence Calculator Calculate cycling cadence (RPM) from speed, or speed from RPM. Covers gear ratio, wheel size, tire size, with a cadence-vs-speed chart and optimal range guide.
Open Birth Year Calculator Find your birth year from your age and the reference date. See the exact formula, birthday adjustment rule, generation, and a decade-by-decade age timeline.
Open Birthday Countdown Calculator Find out exactly how many days, weeks, and hours are left until your next birthday. See the age you are turning, the day of the week, and your next milestone.
Open Biweekly Pay Calculator Convert hourly, daily, weekly, monthly, or annual pay to a biweekly paycheck in seconds. See all pay period equivalents with optional time-off adjustments.
Open Blood Pregnancy Test: What Do HCG Results Mean? Enter your quantitative hCG blood test result and gestational week to get an instant interpretation, weekly range comparison, and doubling-time analysis.
Open Board-on-Board Fence Calculator Calculate pickets, posts, and rails for a board-on-board fence. Enter fence length, board width, and overlap for an instant material count and optional cost estimate.
Open Bread Spreads Calculator Calculate how long a jar of spread lasts, what it costs per week, and how many calories you consume. Covers butter, peanut butter, Nutella, jam, hummus and more.
Open California Overtime Calculator Calculate California overtime pay with daily OT (over 8 hrs), double time (over 12 hrs), weekly OT (over 40 hrs), and 7th consecutive day rules.
Open CC to Liter Converter Convert cubic centimeters (cc) to liters instantly. Also converts liters back to cc, plus milliliters, fluid ounces, and cubic inches. Shows formula and worked example.
Open CC to OZ Converter Convert cubic centimeters (cc/mL) to US or Imperial fluid ounces instantly. Includes the formula, a worked example, a conversion table, and reverse OZ to CC.
Open Celsius Converter Convert Celsius to Fahrenheit, Kelvin, Rankine, Delisle, Newton, Reaumur, and Romer instantly. See the formula and a step-by-step worked example.
Open Cent to Square Meter Converter Convert cents to square meters instantly. Get sq ft, sq yards, acres and guntha too. Includes reverse conversion, reference table, and worked examples.
Open Center of a Circle Calculator Find the center of a circle from the standard equation, general equation, or three points on the circle. Shows full working steps, radius, and a labeled diagram.
Open Center of Ellipse Calculator Find the center of any ellipse from its equation, vertices, co-vertices, or foci. Get (h, k), area, circumference, eccentricity, and the standard form instantly.
Open Centigrade to Celsius Converter Centigrade and Celsius are the same scale, renamed in 1948. Enter any temperature and instantly see its value in Celsius, Fahrenheit, Kelvin, and Rankine.
Open Centimeter Calculator Convert centimeters to inches, feet, meters, millimeters, yards, and miles instantly. See the step-by-step math, a conversion chart, and worked examples.
Open Centor Score Calculator (Modified/McIsaac) Calculate the Modified Centor Score (McIsaac) to estimate Group A Strep probability in pharyngitis. Get a score, GAS probability, and antibiotic guidance instantly.
Open Centroid of a Triangle Calculator Find the centroid coordinates of any triangle from its three vertices. Also get all three median lengths, triangle area, perimeter, and type classification.
Open CGS System of Units Converter Convert CGS units to SI instantly: dyne to newton, erg to joule, gauss to tesla, barye to pascal, poise to Pa-s, and 6 more physical quantities with exact factors.
Open Check Similarity in Right Triangles Calculator Check if two right triangles are similar. Enter two sides of each triangle, get the similarity verdict, scale factor, all sides, and a step-by-step ratio proof.
Open Circle Formula Calculator Calculate any circle property from any other. Enter radius, diameter, circumference, or area to instantly solve for all remaining values with step-by-step working.
Open Circle Length Calculator Calculate circle circumference, arc length, chord length and sector area from any two known values. Supports metric and imperial units, degrees and radians.
Open Circle Measurements Calculator Calculate any circle measurement instantly. Enter radius, diameter, circumference, or area and get all other values plus arc length, sector area, and chord length.
Open Circle Perimeter Calculator Calculate the perimeter (circumference) of a circle from its radius, diameter, or area. Get all four circle properties instantly with step-by-step working.
Open Circumcenter Calculator Find the circumcenter of any triangle from three vertex coordinates. Get circumcenter (x, y), circumradius, side lengths, area, and triangle type with step-by-step working.
Open Circumference and Area of a Circle Calculator Calculate any circle property instantly: enter radius, diameter, circumference, or area and get all four values with step-by-step workings in metric or imperial units.
Open CM Height Conversion Calculator Convert height between centimeters, feet and inches, meters, and total inches. Bidirectional: enter cm or feet+inches. Instant results with step-by-step math.
Open cm to ft in. Converter Convert centimeters to feet and inches instantly. See the full breakdown, decimal feet, total inches, fractional inches, and the reverse ft+in to cm conversion.
Open CM to Inches Converter Convert centimeters to inches instantly. Get decimal inches, fractional inches (nearest 1/64), and a feet+inches breakdown. Reverse inches-to-cm included.
Open cm to km Conversion Calculator Convert centimeters to kilometers instantly. Enter cm or km for a two-way result plus meters, millimeters, feet and miles. Formula and reference table included.
Open cm to m Converter Convert centimeters to meters instantly. Enter any cm value to get meters, plus the reverse m-to-cm result, millimeters, feet, and inches in one step.
Open cm to mm Converter Convert centimeters to millimeters instantly. Enter any cm value and get mm, plus reverse mm-to-cm, with the formula, worked example, and a reference table.
Open CO2 Breathing Emission Calculator Calculate how much CO2 you exhale per hour, day, and year based on your height, weight, and activity level. Uses the Persily-de Jonge formula with DuBois surface area.
Open Combination without Repetition Calculator Calculate combinations without repetition. Enter n and r to find C(n,r), compare with permutations, and explore the step-by-step working and nCr reference table.
Open Combinations with Repetition Calculator Calculate combinations with repetition using C(n+r-1, r). Get the formula, step-by-step work, a no-repetition comparison, and every combination listed for small inputs.
Open Combined Ratio Calculator Calculate the combined ratio for any insurance company. Enter loss ratio and expense ratio, or raw dollar amounts, to assess underwriting profitability instantly.
Open Common Denominator Calculator Find the least common denominator for up to 4 fractions instantly. Shows prime factorization, equivalent fractions, and full step-by-step work. Free online tool.
Open Common Factor Calculator Find all common factors of two or more integers instantly. See the GCF, LCM, individual factor lists, and a full prime-factorization step-by-step breakdown.
Open Completing the Square Calculator Complete the square for any quadratic ax^2 + bx + c = 0. Get step-by-step workings, vertex form, roots, and discriminant analysis instantly.
Open Complex Number to Polar Form Calculator Convert a + bi to polar form and exponential form instantly. Outputs modulus, argument in degrees and radians, quadrant, conjugate, and full step-by-step working.
Open Complex Number to Rectangular Form Calculator Convert a complex number from polar form (r, phi) to rectangular form a + bi instantly. Supports degrees and radians, shows every step, and converts back.
Open Conversion Calculator Convert length, weight, temperature, volume, area, speed, and time units instantly. See the formula and step-by-step math for every conversion.
Open Coordinate Distance Calculator Calculate the distance between two points in 2D or 3D space instantly. Shows the full step-by-step Euclidean distance formula with your numbers substituted in.
Open Cos-1 Calculator (Arccosine) Find the arccosine of any value from -1 to 1. Get the angle in degrees and radians with step-by-step working, exact-value reference table, and triangle solver.
Open Cos Inverse Calculator (Arccos) Calculate the inverse cosine (arccos) of any value from -1 to 1. Get the angle in degrees, radians, and pi-radians, with steps, a curve visual, and a reference table.
Open Cosine Triangle Calculator Solve any triangle with the Law of Cosines. Enter SSS (3 sides) or SAS (2 sides and included angle) to find all angles, area, perimeter, inradius, and circumradius.
Open Cost of Having a Baby Calculator Estimate your total cost of having a baby: delivery, childcare, diapers, feeding, gear, and clothing. Adjust for insurance, delivery type, and spending tier.
Open Count Hours Calculator Count hours between any two times instantly. Supports 12/24-hour formats, break deductions, overnight shifts, and decimal hours conversion for payroll.
Open CPS Calculator - Clicks Per Second Calculate your clicks per second (CPS) from total clicks and time. Get your skill level, see technique benchmarks, and find out what a good CPS score looks like.
Open Cross Exchange Rate Calculator Calculate a cross exchange rate between any two currencies using a shared pivot currency. Supports bid/ask spread mode, step-by-step math, and 6 major currency pairs.
Open CSS Aspect Ratio Calculator Calculate aspect ratios instantly. Get the simplified ratio, decimal value, padding-bottom percentage for the CSS padding hack, and the modern aspect-ratio CSS property value.
Open Cube Density Calculator Calculate the density of any cube from its mass and side length, space diagonal, or face diagonal. Solve for mass or side length in metric or imperial units.
Open Cubic Unit Cell Calculator Calculate lattice parameter, atomic radius, unit cell volume, density, packing efficiency, and coordination number for simple cubic, BCC, and FCC crystal structures.
Open Cubic Feet of a Cylinder Calculator Calculate the cubic feet of a cylinder instantly. Enter diameter (or radius) and height in any unit - feet, inches, cm, or meters - and get volume in ft3, gallons, and liters.
Open Cubic Inches of a Cylinder Calculator Calculate the volume of any cylinder in cubic inches. Enter radius or diameter and height for instant results, plus hollow cylinder and unit conversion modes.
Open Cubic Inches to Gallons Converter Convert cubic inches to US or UK gallons instantly. See the formula, step-by-step math, fluid ounces, quarts, liters, and a reference table of common volumes.
Open Cubic Yards in a Cylinder Calculator Calculate the volume of a cylinder in cubic yards from any unit - inches, feet, or metres - plus optional material cost. Instant results with step-by-step working.
Open Cuboid Surface Area Calculator Calculate the total and lateral surface area of a cuboid instantly. Enter length, width, and height in metric or imperial units, with step-by-step working shown.
Open Cuboid Volume Calculator Calculate the volume, surface area, lateral area, space diagonal, and all three face diagonals of a cuboid. Switch between metric and imperial units instantly.
Open Custom Dice Roller Calculator Roll any number of custom dice (D4 to D100) with a modifier. Get the expected value, standard deviation, min/max, and the full probability distribution instantly.
Open D20 Dice Roller Roll one or more d20s with advantage, disadvantage, or a flat modifier. See the probability of meeting any target number and the expected value instantly.
Open DART Rate Calculator Calculate your OSHA DART rate instantly. Enter incidents and hours worked to get your Days Away, Restricted, or Transferred rate with industry benchmark comparison.
Open DASI Calculator (Duke Activity Status Index) Calculate your Duke Activity Status Index score, estimated VO2 max, and METs from the validated 12-item DASI questionnaire for preoperative cardiac risk assessment.
Open Date Countdown Calculator Count the exact days, weeks, months, and business days between any two dates. See the full breakdown instantly, past or future.
Open Date of Birth Calculator Enter your date of birth to get your exact age in years, months, days, hours and seconds, your zodiac sign, generation, next birthday countdown, and more.
Open Dating Theory Calculator Use the optimal stopping dating theory calculator to find how many people to date before settling down. Based on the mathematical 37% rule (secretary problem).
Open Day Converter Convert days to hours, minutes, seconds, weeks, months and years instantly. Supports decimals, shows a clock-style breakdown, and explains the conversion math step by step.
Open Day Countdown Calculator Count days until any date instantly. See the exact breakdown by years, months, weeks, weekdays and weekend days. Free online countdown calendar.
Open Day of the Week Calculator Find the exact day of the week for any date - past, present, or future. See the day number, ordinal position in the month, leap-year status, and a weekday fact.
Open Days Old Calculator Find out exactly how many days old you are. Enter your birthdate to get your age in days, weeks, months, hours, and minutes, plus your next big day milestone.
Open Days to Months Calculator Convert any number of days to months instantly. See the full breakdown into years, months, and remaining days, with a step-by-step worked example.
Open Days Until December Calculator Count the days, weeks, hours and business days until December 1 from any start date. See a full time breakdown and December holiday milestones instantly.
Open Days Until Valentine's Day Calculator Find out exactly how many days, weeks, hours, and weekdays are left until Valentine's Day. Pick any start date and get a full breakdown instantly.
Open dBm to Watts Calculator Convert between dBm and watts. Enter dBm to get watts, milliwatts, and dBW, or enter watts to get dBm. Includes step-by-step working and a common power levels reference table.
Open Decagon Area Calculator Calculate the area of a regular decagon from side length, perimeter, circumradius, or inradius. Get area, perimeter, apothem, and angles instantly.
Open Decagon Calculator Calculate the area, perimeter, circumradius, inradius, and all 4 diagonal lengths of a regular decagon. Enter any one property and solve the rest instantly.
Open Decimal Time Converter Convert decimal time to hours, minutes, and seconds - or reverse from hh:mm:ss to decimal. Supports days, hours, minutes, and seconds as the source unit.
Open Degrees Minutes Seconds to Decimal Degrees Converter Convert DMS (degrees, minutes, seconds) to decimal degrees. GPS lat/lon with N/S/E/W hemispheres, reverse DD to DMS, show-your-work steps, and landmark reference table.
Open Degrees to Minutes Converter Convert decimal degrees to degrees, minutes, and seconds (DMS) or to decimal minutes instantly. Also reverse: DMS back to decimal degrees. Free online tool.
Open Degrees to Radians Converter Convert degrees to radians instantly. Get the exact pi-fraction, decimal radians, and the sine, cosine, and tangent for any angle. Reverse conversion included.
Open Degrees to Seconds Converter Convert decimal degrees to arcseconds instantly. See the full DMS breakdown (degrees, minutes, seconds), the reverse conversion, and a worked example.
Open Density Conversion Calculator Convert density between 20 units including kg/m³, g/cm³, g/L, lb/ft³, lb/in³ and slug/ft³. Instant results with worked steps and a material reference table.
Open Density Mass Volume Calculator Solve for density, mass or volume instantly. Enter any two of the three values, choose metric or imperial units, and get the third with a step-by-step breakdown.
Open Density of a Cylinder Calculator Calculate the density of a solid or hollow cylinder from its mass, radius, and height. Metric and imperial units, step-by-step math, and material reference table.
Open Density to Mass Calculator Calculate mass from density and volume instantly using m = rho x V. Choose from 6 density units, 8 volume units, 7 mass output units, and see the step-by-step working.
Open Detention Time Calculator Detention time calculator for water and wastewater basins. Enter volume and flow rate, select a process, and get DT in minutes, hours, or days.
Open Diameter of a Circle Calculator Calculate the diameter of a circle from its radius, circumference, or area instantly. See all four circle properties with step-by-step working in metric or imperial units.
Open Diameter of a Cone Calculator Find the base diameter of any cone from height, slant height, volume, or surface area. Five solve modes, metric and imperial units, full step-by-step working.
Open Diameter of a Cylinder Calculator Find the diameter of any cylinder from its volume and height, radius, or circumference. Instant metric and imperial results with step-by-step math.
Open Diameter to Radius Calculator Convert diameter to radius instantly, or reverse from radius to diameter. Also get circumference and area with metric and imperial unit support.
Open Diamond Carat Calculator Calculate diamond carat weight from mm dimensions for 12 shapes: round, oval, princess, emerald, cushion and more. Uses GIA-standard formulas with girdle adjustment.
Open Diamond Weight Calculator Estimate a diamond's carat weight from its millimetre dimensions for 12 shapes. Includes depth %, L/W ratio, girdle adjustment, and a cut-quality note.
Open Diaper Calculator Find out how many diapers your baby needs and what they cost. Enter age, days to stock up, and box price to get a full cost and week-by-week breakdown.
Open Dimensional Analysis Calculator Convert any physical quantity with step-by-step factor-label (unit-factor) dimensional analysis. Supports 12 quantity types, 70+ units, and shows all conversion work.
Open DIN Calculator - How to Adjust Ski Bindings Find your ISO 11088 DIN ski binding setting from weight, height, age, boot sole length, and skier type. Instant result with a full worked explanation.
Open Distance Converter Convert any distance instantly: kilometers, miles, meters, feet, inches, nautical miles, light-years and 20 units total. See the formula and conversion steps.
Open Divisor Calculator: All Divisors, Count, Sum and Factorization Find all divisors of any positive integer instantly. Get the divisor list, count, sum, prime factorization, proper divisors, GCD, and common divisors of two numbers.
Open Decimeter (dm) Converter Convert decimeters to meters, centimeters, millimeters, inches, feet, yards, miles and more. Instant two-way conversion with formulas and a worked example.
Open Dodecagon Area Calculator Calculate the area of a regular dodecagon from side length, perimeter, circumradius, or inradius. Includes diagonals, angles, and a step-by-step breakdown.
Open Completing the Square Calculator: Quadratic Solver with Steps Solve any quadratic equation ax^2 + bx + c = 0 by completing the square. See every step, vertex form, discriminant, and real or complex roots instantly.
Open Dog Walking Benefits Calculator Calculate calories burned walking your dog, estimated steps, weekly WHO activity minutes, and your dog calorie burn. Supports fetch and tug of war bonus activities.
Open Double Angle Calculator Enter any angle in degrees or radians and get sin(2θ), cos(2θ), tan(2θ), csc(2θ), sec(2θ), and cot(2θ) with full step-by-step working.
Open Double Angle Identities Calculator Calculate all double-angle identities instantly. Enter any angle in degrees or radians to get sin(2theta), cos(2theta) and tan(2theta) with step-by-step substitution.
Open Elapsed Time Calculator Find elapsed time between two clock times instantly. Get days, hours, minutes and seconds, a step-by-step breakdown, and a visual timeline. Works overnight.
Open Elevation Grade Calculator Calculate road or trail grade as a percentage, angle in degrees, and 1-in-X ratio from rise and run. Includes ADA, highway, and treadmill grade reference table.
Open Ellipse Circumference Calculator Calculate the circumference of any ellipse using four approximation formulas: Ramanujan II, Ramanujan I, RMS, and infinite series. Compare accuracy instantly.
Open Ellipse Perimeter Calculator Calculate the perimeter (circumference), area, and eccentricity of any ellipse. Compares Ramanujan, Euler, and series approximations with step-by-step math.
Open D&D 5e Encounter Difficulty Calculator Calculate D&D 5e encounter difficulty. Enter party levels and monster CRs to get Easy, Medium, Hard, or Deadly ratings, adjusted XP, and per-player XP awards.
Open Energy Conversion Calculator Convert energy between 17 units: joules, kWh, BTU, kcal, therms, foot-pounds, electronvolts and more. Formulas, worked examples and a reference table included.
Open Engagement Rate Calculator Calculate engagement rate by reach, followers, impressions, or views. Get a platform-specific benchmark, cost per engagement, and a show-your-work panel. Free and instant.
Open Equation of a Circle with Diameter Endpoints Calculator Enter two diameter endpoints to get the circle equation in standard, general, and parametric form, plus center, radius, area, and circumference with step-by-step math.
Open Equilateral Triangle Calculator Calculate the area, height, perimeter, inradius, and circumradius of an equilateral triangle from any single known value. Instant results with step-by-step working.
Open Equivalent Ratio Calculator Find a missing ratio value, check if two ratios are equivalent, simplify any ratio, or scale it up or down. Instant step-by-step results with no sign-up.
Open EU to US Shoe Size Calculator Convert EU shoe sizes to US men's, US women's, UK, and Japan sizes instantly. Includes child sizes, foot length in cm and inches, and a full reference table.
Open Euclidean Algorithm Calculator Find the GCD of two integers step by step using the Euclidean algorithm. Computes LCM, Bezout coefficients, coprimality, and modular inverse with a full division table.
Open Even Parity Bit Calculator Generate the even parity bit for any binary word, see the encoded message, and verify received data for single-bit errors. Step-by-step workings included.
Open Exact Value of Trig Functions Calculator Find the exact value of sin, cos, tan, cot, sec, and csc for any angle. Instant symbolic results for all special angles, with a step-by-step breakdown.
Open Exoplanet Travel Planner Calculator Plan an interstellar trip to real exoplanets. Calculate Earth-frame and ship-frame travel time, relativistic time dilation, crew supplies, and fuel mass ratio.
Open Exterior Angles of a Triangle Calculator Find all three exterior angles of any triangle. Enter two angles and get every exterior angle instantly, with the exterior angle theorem shown step by step.
Open Fahrenheit Converter Convert Fahrenheit to Celsius, Kelvin, Rankine, and Reaumur instantly. See step-by-step working, all four conversions at once, and a key temperature reference table.
Open False Positive Calculator Calculate false positive rate, PPV, NPV, likelihood ratios, F1, and accuracy from prevalence, sensitivity, and specificity. Includes a full confusion-matrix breakdown.
Open Fatigue Severity Scale (FSS) Calculator Calculate your Fatigue Severity Scale (FSS) score instantly. Rate 9 validated statements, see your mean score, severity band, and clinical interpretation.
Open Feet to Miles Converter Convert feet to miles instantly with the exact ft to mi formula. Get the result in miles, yards, meters and kilometers, plus a worked example and reference table.
Open Fence Material Calculator Calculate how many fence posts, rails, pickets, and bags of concrete you need for any wood fence project. Supports imperial and metric with a material cost estimate.
Open Fibonacci Retracement Calculator Calculate Fibonacci retracement and extension levels for stocks, forex, or crypto. Enter a swing high and low to get levels at 23.6%, 38.2%, 61.8%, and beyond.
Open Fifth Root Calculator Calculate the fifth root of any positive or negative number instantly. See the step-by-step working, the inverse check, and the full curve chart.
Open First Quartile Calculator Paste your data to find Q1, Q2 (median), Q3, IQR, range, and Tukey outlier bounds instantly. Choose from three quartile methods with a full step-by-step breakdown.
Open Fish Mercury Calculator: Safe Weekly Servings by Species and Weight Calculate mercury in fish by species and serving size. See your mcg intake, % of the EPA weekly limit, and safe servings per week based on your weight and life stage.
Open Florida Overtime Calculator Calculate Florida overtime pay instantly. Enter your hourly rate and hours worked to get regular pay, overtime pay, and total weekly earnings under FLSA rules.
Open Fluid Ounces to Pounds Conversion Convert fluid ounces to pounds instantly for water, milk, honey, oil, and 20+ other liquids. Switch between fl oz to lb and lb to fl oz with one click.
Open Foci of an Ellipse Calculator Calculate the foci, eccentricity, vertices, area, and circumference of any ellipse. Enter the semi-major and semi-minor axes to get full results with step-by-step working.
Open Fourth Root Calculator Calculate the fourth root of any positive number instantly. Step-by-step working, prime factorization method, inverse-power check, and a perfect fourth powers table.
Open Fractional Odds Calculator Convert fractional odds to decimal, American, and implied probability instantly. Enter any odds format and get profit and total payout for your stake.
Open Free Fall Distance Calculator Calculate free fall distance, time, final velocity, and initial velocity in metric or imperial units. Covers drop from rest, thrown downward, and reverse-solve modes.
Open Free Fall Height Calculator Calculate free fall height, drop time, impact velocity, or initial velocity with metric and imperial units. Covers Earth, Moon, Mars, and 5 other bodies.
Open Free Fall Time Calculator Free fall calculator: find fall time, distance, and impact speed for any height and gravity. Choose metric or imperial, pick a planet, and see the step-by-step math.
Open Free Fall Velocity Calculator Calculate free fall velocity, distance, and fall time in metric or imperial units. Supports initial velocity, custom gravity, and 9 planet presets.
Open Free Testosterone Calculator with Bioavailable Levels Calculate free and bioavailable testosterone from total testosterone, SHBG, and albumin using the Vermeulen formula. Instant results with age and sex reference ranges.
Open Frequency to Wavelength Calculator Convert any frequency to wavelength instantly. Supports EM waves, sound, and custom media. Includes wavenumber, period, ITU band, and dipole antenna length.
Open Friction Coefficient Calculator Calculate the coefficient of friction, friction force, or normal force. Covers static vs kinetic mode, inclined-plane solver, and a material reference table.
Open Friction Force Calculator Calculate friction force, normal force, or coefficient of friction instantly. Supports static and kinetic modes, inclined surfaces, 15 material presets, and full worked steps.
Open Feet to Meters Converter Convert feet to meters instantly with the exact SI factor 0.3048. Supports feet-and-inches input, bidirectional mode (m to ft), worked steps, and a full conversion table.
Open Fuel Consumption Calculator Calculate fuel consumption and fuel economy instantly: enter distance and fuel used to get MPG, km/L and L/100km, plus trip cost and CO2 emissions.
Open Fuel Distance Calculator Calculate how far you can drive on your fuel, how much gas a trip needs, or your real MPG. Metric and imperial, with trip cost and a range chart.
Open Fuel Mileage Calculator Calculate fuel mileage in MPG, km/L or L/100km from odometer readings or trip distance. Get trip cost, annual fuel cost, and a comparison to the US average.
Open Grams to Pounds Converter (g to lbs) Convert grams to pounds and ounces instantly. See the formula, a step-by-step breakdown, lb+oz combined result, and a full reference table from 1 g to 5000 g.
Open Grams to Teaspoons Converter (g to tsp) Convert grams to teaspoons for sugar, salt, flour, butter, honey and 40+ ingredients. Bidirectional - enter grams or teaspoons. US and metric teaspoon sizes supported.
Open GAA Calculator (Goals Against Average) Calculate a goalkeeper's Goals Against Average (GAA) for hockey, soccer, lacrosse, or water polo. Enter goals allowed and minutes played for an instant result.
Open Gallons to Cubic Feet Converter Convert gallons to cubic feet instantly. Supports US liquid, US dry, and UK imperial gallons. Bidirectional: enter cubic feet to get gallons back.
Open Gallons to Grams Converter Convert US or UK gallons to grams for water, milk, flour, oil, honey, sugar, fuel and more. Enter any custom density to get an instant, accurate mass result.
Open Gas Density Calculator Calculate gas density from pressure, temperature, and molar mass using the ideal gas law. Choose from 10 preset gases, set your units, and reverse-solve for P, T, or M.
Open GCD Calculator Find the greatest common divisor (GCD) of up to five integers instantly. Shows the Euclidean algorithm step by step, prime factorizations, and the matching LCM.
Open Gear Ratio RPM Calculator Calculate gear ratio from tooth counts, find output RPM or input RPM, and estimate vehicle speed in MPH. Includes worked steps, chart, and reference table.
Open Gear Ratio Speed Calculator Calculate vehicle speed from gear ratio, engine RPM, axle ratio, and tire size. Shows speed in every gear, RPM at cruise, and the full gear-by-gear breakdown.
Open Gender Pay Gap Calculator Calculate the gender pay gap between men and women using mean pay, median pay and bonus gap formulas. Shows quartile breakdown and bonus participation rates instantly.
Open Georgia Overtime Calculator Calculate Georgia overtime pay instantly. Enter your hourly rate and hours worked to see time-and-a-half earnings, total gross pay, and effective hourly rate.
Open Goalie Save Percentage Calculator Calculate hockey goalie save percentage, GAA, GSAA and quality start rate from shots, goals and minutes. Includes benchmarks by level and a game log.
Open Gram to Liter Conversion Convert grams to liters (or liters to grams) for 35+ substances including water, flour, sugar, oil, milk and honey. Enter a mass or volume and choose an ingredient.
Open Grams to ml Converter Convert grams to milliliters (or ml to grams) for water, flour, sugar, butter, oil, honey, milk and 20+ cooking ingredients. Uses correct density per ingredient.
Open Grams to Fluid Ounces Converter Convert grams to US or UK fluid ounces for water, flour, sugar, butter, oil, milk, and 20+ other ingredients. See the step-by-step formula and a quick-reference table.
Open Greatest Common Denominator Calculator Find the greatest common denominator of up to 6 integers instantly. See step-by-step working via prime factorisation, the Euclidean algorithm, or factor listing.
Open Greatest Common Divisor Calculator Find the greatest common divisor of up to 10 numbers instantly. Shows factor lists, prime factorization, and the Euclidean algorithm step by step.
Open Greatest to Least Calculator Sort any list of numbers from greatest to least instantly. Supports integers, decimals, fractions, percentages, and negatives. Get min, max, range, mean, and median.
Open Half Marathon Pace Calculator Calculate your half marathon finish time from pace, or find the pace you need for a goal time. Get per-mile and per-km pace, splits every 5 km, and training zone paces.
Open Hardness Conversion Calculator: HRC, HRB, HV, HB, HRA Convert metal hardness between Rockwell C (HRC), Rockwell B (HRB), Rockwell A (HRA), Vickers (HV), Brinell (HB), and tensile strength. Based on ASTM E140.
Open Headphone Power Calculator Calculate power, voltage, and current your amplifier needs to drive any headphones to your target loudness. Enter sensitivity, impedance, and desired SPL.
Open Height of a Square Pyramid Calculator Calculate the height of a square pyramid from base edge, slant height, lateral edge, volume, or surface area. Instant results with step-by-step working.
Open Heptagon Area Calculator Calculate the area of a regular heptagon from its side length, apothem, or circumradius. Instant results with perimeter, inradius, and step-by-step formula.
Open Heptathlon Score Calculator Calculate your heptathlon score using official IAAF / World Athletics tables. Enter all 7 event results and get individual points, total score, and performance level.
Open Hexagonal Pyramid Calculator Calculate the volume, total surface area, lateral area, base area, slant height, apothem, and face area of a regular hexagonal pyramid. Metric and imperial units.
Open Hexagonal Pyramid Surface Area Calculator Calculate the total, lateral, and base surface area of a hexagonal pyramid instantly. Enter base edge and height in metric or imperial units with step-by-step working.
Open Hilbert's Hotel Paradox Calculator Explore Hilbert's infinite hotel paradox with worked calculations for finite arrivals, infinite new guests, and infinite buses with infinite passengers.
Open Hollow Cylinder Volume Calculator Calculate the shell volume, inner cavity volume, and wall thickness of any hollow cylinder or pipe. Supports metric and imperial units with step-by-step working.
Open Hour Converter Convert hours to minutes, seconds, milliseconds, days, weeks, months and years instantly. See the clock breakdown and full conversion table with worked steps.
Open Hour Countdown Calculator Calculate the exact number of hours between any two dates and times. Get a full breakdown into days, hours, minutes, and seconds - free and instant.
Open Hourly to Annual Salary Calculator Convert hourly pay to annual salary instantly. Includes overtime, double-time, weekly, monthly, and daily breakdowns. Supports USD, EUR, GBP, and more.
Open Hours Pay Calculator Convert any pay period (hourly, daily, weekly, bi-weekly, monthly or annual) instantly. Includes overtime at 1.5x, holiday adjustments, and a full pay breakdown.
Open Hours to Days Calculator Convert hours to days instantly with this free calculator. Get whole days and remaining hours, plus a reverse days-to-hours mode and a full conversion table.
Open Hours to Decimal Calculator Convert hours, minutes, and seconds to decimal hours instantly. Supports reverse conversion and payroll pay calculation. Includes a full minute-to-decimal chart.
Open Hours to Minutes Converter Convert hours to minutes instantly. Enter whole or decimal hours, or h:m:s time. Get total minutes, total seconds, and hh:mm:ss format with a step-by-step breakdown.
Open Hours to Weeks Converter Convert hours to weeks instantly. Choose calendar weeks (168 h) or work weeks (40 h), get a full breakdown into weeks, days, and remaining hours, plus reverse conversion.
Open Hours to Years Converter Convert hours to years instantly. See the equivalent in years, months, weeks, days, minutes, and seconds. Includes reverse converter and worked examples.
Open How Much Mashed Potatoes Per Person Calculator Calculate exactly how many pounds of raw potatoes you need per person for any crowd size, with butter, cream, and occasion-specific serving guidance.
Open How Old Am I Calculator Find your exact age in years, months, weeks, days, hours, minutes and seconds. See your next birthday countdown, age milestones, and a full breakdown instantly.
Open How Old Was I Calculator Find out exactly how old you were on any date in history. Enter your birthday and a target date to get your age in years, months, days, weeks, hours and more.
Open Pregnancy Weight Gain Calculator Find your recommended pregnancy weight gain by week using your pre-pregnancy BMI. Based on 2009 IOM guidelines with metric and imperial unit support.
Open HR Software ROI Calculator Calculate the ROI of HR software instantly. See annual savings from admin time, payroll errors, onboarding, and turnover, plus your payback period and net benefit.
Open Hydraulic Retention Time (HRT) Calculator Calculate hydraulic retention time (HRT) from reactor volume and flow rate. Metric and imperial units, multiple time scales, and reverse-solve for volume or flow.
Open i Calculator - Powers of i and Imaginary Numbers Calculate any power of the imaginary unit i. See i^n simplified, the 4-cycle pattern explained step by step, and the square root of any negative number.
Open Ideal Egg Boiling Calculator Calculate the exact boiling time for a runny, soft, medium, or hard egg. Adjusts for egg size, starting temperature, and altitude using real thermal-diffusion physics.
Open Ideal Gas Pressure Calculator Calculate ideal gas pressure from moles, volume, and temperature using PV = nRT. Supports Pa, kPa, atm, bar, psi and multiple volume and temperature units.
Open Ideal Gas Law Calculator (PV = nRT) Solve the ideal gas law PV = nRT for pressure, volume, moles, or temperature. Choose metric or imperial units, see the step-by-step working, and explore charts.
Open Illinois Overtime Calculator Calculate Illinois overtime pay instantly. Enter your hourly rate and hours worked to see regular pay, time-and-a-half earnings, and total weekly take-home.
Open Imperial Calculator Convert between imperial units and metric instantly. Length (inches, feet, miles), weight (ounces, pounds, stone), volume (cups, pints, gallons), area, and temperature.
Open Imperial to Metric Conversion Calculator Convert imperial to metric instantly: inches to cm, feet to m, miles to km, pounds to kg, Fahrenheit to Celsius, gallons to litres, and acres to hectares.
Open Inches to Centimeters Converter Convert inches to centimeters instantly. Enter a decimal or fractional inch value (or feet + inches) and get the exact cm result with the formula shown.
Open Inch to Meter Calculator Convert inches to meters instantly with our free calculator. Enter inches or meters for two-way conversion, see the formula, worked steps, and a full reference table.
Open Inches to Yards Converter Convert inches to yards instantly with step-by-step working. Also shows feet, centimetres, metres, and millimetres. Free, no sign-up required.
Open Inscribed Angle Calculator Calculate the inscribed angle, central angle, arc length, and radius of a circle instantly. Supports all four solve modes with step-by-step working.
Open Integration by Completing the Square and Substitution Calculator Complete the square in a quadratic denominator, apply u-substitution, and get the exact integral result with every step shown. Free online math tool.
Open Interior and Exterior Triangle Angles Calculator Enter any two angles of a triangle to find all three interior angles and the three exterior angles. Works in degrees or radians with step-by-step working.
Open Inverse Cosine Calculator Find arccos(x) in degrees, radians, and gradians. Enter a cosine value or two triangle sides, see worked steps, and explore a reference table of common values.
Open Inverse Sine Calculator Calculate the inverse sine (arcsin) of any value from -1 to 1. Get the angle in degrees and radians instantly, with a worked triangle example and reference table.
Open Inverse Square Law Calculator Calculate how intensity falls off with distance using the inverse square law. Find new intensity, solve for distance, or compute dB attenuation for sound.
Open Involute Function Calculator Calculate inv(α) = tan(α) − α for any pressure angle in degrees or radians. Gear tooth thickness, pressure angle at any diameter, and a step-by-step worked solution.
Open Irregular Trapezoid Area Calculator Calculate the area of an irregular (scalene) trapezoid using bases and height, four side lengths, or four vertex coordinates. Metric and imperial units.
Open Is it a Right Triangle Calculator Check whether any triangle is a right triangle using three side lengths, two angles, or two sides and an angle. Instant result with step-by-step math.
Open Isosceles Right Triangle Calculator Calculate the legs, hypotenuse, altitude, area, and perimeter of a 45-45-90 isosceles right triangle. Enter any one value and get all others instantly.
Open Isosceles Right Triangle Hypotenuse Calculator Calculate the hypotenuse, leg, height, area, and perimeter of an isosceles right triangle. Enter any one measurement and get all the rest instantly.
Open Isosceles Trapezoid Area Calculator Calculate the area, perimeter, height, diagonal length, and base angles of an isosceles trapezoid instantly. Enter any two bases and the leg or height.
Open Isosceles Trapezoid Calculator Calculate the area, perimeter, height, diagonal, circumradius, median and all angles of an isosceles trapezoid. Enter any three dimensions to solve instantly.
Open Isosceles Triangle Angles Calculator Calculate every property of an isosceles triangle: vertex angle, base angles, height, area, perimeter, inradius, and circumradius. Four solve modes, metric or imperial.
Open Isosceles Triangle Area Calculator Calculate the area of any isosceles triangle from leg and base, leg and height, or vertex angle. Get perimeter, altitudes, inradius and circumradius instantly.
Open Isosceles Triangle Height Calculator Calculate the height of an isosceles triangle from leg and base. Get apex height, leg height, area, perimeter, vertex angle, base angle, and radii instantly.
Open Isosceles Triangle Side Calculator Find every property of an isosceles triangle: legs, base, height, angles, perimeter, area, inradius, and circumradius. Free, instant, step-by-step working shown.
Open Joules to Volts Calculator Convert joules to volts using charge (V = E/Q) or capacitance (V = sqrt(2E/C)). Get instant results, step-by-step math, and a voltage chart.
Open Kalkulator kopert komunijnych Oblicz, ile pieniedzy wlozyc do koperty na Pierwsza Komunie w 2026 roku. Uwzglednia relacje, koszt talerza i wielkosc miejscowosci. Wynik w sekunde.
Open Katha to Square Feet Converter Convert katha to square feet instantly for West Bengal, Bihar, Assam, Nepal and more. Includes reverse conversion, square meters, and a full regional reference table.
Open Kelvin Converter Convert Kelvin to Celsius, Fahrenheit, Rankine, Delisle, Newton, Reaumur, and Romer instantly. Enter any scale and get all seven equivalents with step-by-step formulas.
Open Kelvin to Celsius Converter Convert Kelvin to Celsius instantly. Get degrees C with step-by-step working, a landmark reference table, bonus Fahrenheit output, and reverse Celsius-to-Kelvin mode.
Open Kelvin to Fahrenheit Converter Convert Kelvin to Fahrenheit with the K to degF formula, step-by-step working, Celsius output, reverse degF to K mode, and a milestone reference table.
Open kg/cm2 to psi Converter Convert kg/cm2 to psi (and psi to kg/cm2) instantly. See the step-by-step formula, multi-unit results in bar, kPa, MPa, and atm, plus a reference table.
Open kg to mL Converter Convert kilograms to milliliters for water, milk, flour, sugar, honey, oil and 35+ other ingredients. Enter mass, pick a substance and get the volume instantly.
Open Kilometer Calculator Free kilometer calculator. Enter any length unit and instantly convert to km, miles, feet, meters, yards, inches, centimeters, millimeters, and nautical miles.
Open Kilometers to Miles Calculator Convert kilometers to miles (and miles to km) instantly. See the formula, a step-by-step worked example, a race-distance reference table, and common landmark distances.
Open Knots to mph Converter Convert knots to mph instantly - and get km/h, m/s, and ft/s in the same step. Includes a worked-example panel, Beaufort wind scale, and reverse mph-to-knots mode.
Open kPa Converter Convert pressure from any unit to kPa and back. Covers kPa, Pa, hPa, MPa, bar, mbar, psi, atm, Torr, mmHg, inHg and technical atmosphere with full worked steps.
Open kPa to atm Conversion Convert kilopascals to atmospheres instantly. Enter kPa or atm for a two-way result plus bar, psi, Pa, mmHg, and torr. Formula and worked examples included.
Open kPa to mmHg Conversion Calculator Convert kilopascals to mmHg instantly. Includes reverse mmHg to kPa, blood pressure and blood gas reference ranges, multi-unit outputs, and a worked example.
Open kPa to psi Conversion Instantly convert kilopascals to psi (and back) with a bidirectional pressure calculator. Shows psf, bar, atm, Pa, and mmHg, plus a worked example and reference table.
Open KSI to MPa Converter Convert ksi to MPa (or MPa to ksi) instantly. Includes the exact formula, step-by-step math, and a reference table of common material yield strengths.
Open kVA to Amperage Calculator Convert kVA to amps instantly for single-phase or three-phase systems. Enter apparent power and voltage to get current in amperes, with formulas and reference tables.
Open Lateral Surface Area of a Cylinder Calculator Calculate the lateral (curved) surface area of a cylinder from radius or diameter and height. Metric and imperial units, step-by-step working, and total surface area.
Open Pounds to Grams Converter (lbs to g) Convert pounds to grams instantly using the exact SI factor of 453.59237 g per pound. Includes grams, kilograms, ounce breakdown, reverse mode, and a reference table.
Open Pounds (lbs) Weight Converter Convert pounds (lbs) to kilograms, grams, ounces, stone, metric tons and more. Instant results with the formula, worked example, and a full reference table.
Open Pounds to Stone Converter Convert pounds to stone instantly. Get whole stones, stones and pounds, kilograms, and ounces - with the formula, worked example, and a full reference table.
Open Least Common Denominator Calculator Find the least common denominator for up to 5 fractions instantly. See step-by-step prime factorization, the LCD, and each fraction rewritten with the new denominator.
Open Least Common Multiple (LCM) Calculator Find the least common multiple of up to 5 numbers instantly. See the prime factorisation, GCF method, and listing-multiples method step by step.
Open Least Common Multiple Calculator Find the least common multiple of up to 6 numbers instantly. Shows step-by-step prime factorization, GCD method, and the GCF. Free online LCM calculator.
Open Rectangle Length and Width from Perimeter Calculator Find the length and width of a rectangle from its perimeter and one other value. Enter perimeter plus one side or the area to solve all dimensions instantly.
Open Length of a Line Segment Calculator Calculate the length of a line segment from two endpoints in 2D or 3D. Also finds midpoint, slope, and angle. Instant results with step-by-step working.
Open Length of a Rectangle Calculator Find the length of a rectangle from its area, perimeter, diagonal, or width. Metric and imperial units, step-by-step working, and a live shape diagram.
Open Liter to cc Converter Convert liters to cubic centimetres (cc / cm3) and back. Enter a value in either direction - get mL, fl oz, cups, gallons, cubic inches and more instantly.
Open Liters to Pounds Calculator Convert liters to pounds (or pounds to liters) for water, fuel, milk, oil, honey, and 20+ other substances. Shows the formula, worked steps, and a density table.
Open Loss Ratio Calculator Calculate insurance loss ratio, combined ratio, and target premium in three modes. Includes LAE, claim reserves, expense ratio, and line-of-business benchmarks.
Open Lotka-Volterra Calculator Model predator-prey dynamics with the Lotka-Volterra equations. Get equilibrium populations, oscillation period, conserved quantity, and a live time-series chart.
Open Lower Fence Calculator Calculate the lower fence, upper fence, Q1, Q3, and IQR from any dataset. Detects outliers using Tukey's 1.5 IQR rule with an adjustable multiplier.
Open Lowest Common Denominator Calculator Find the LCD of up to 5 fractions instantly. See equivalent fractions, step-by-step working, and a prime factorization breakdown. Free and ad-supported.
Open Luhn Algorithm Calculator Validate any number with the Luhn algorithm, compute a check digit, or generate a Luhn-valid number. Full step-by-step digit breakdown shown.
Open Meters to Feet Converter Convert meters to feet instantly. Get the decimal feet result, the feet-and-inches breakdown, and a full worked example. Reverse mode converts feet back to meters.
Open Mass to Density Calculator Calculate density from mass and volume, or solve for mass or volume when density is known. Supports metric and imperial units with common material densities.
Open Matched Betting Calculator Calculate your optimal lay stake, exchange liability and guaranteed profit for qualifying bets, free bets (SNR) and free bets (SR). Instant results, no signup.
Open Math Power Calculator Calculate any base raised to any exponent instantly. Supports negative and fractional exponents, reverse-solve for base or exponent, and shows every step.
Open Measurement Converter Convert between 70+ units across 7 categories - length, weight, temperature, volume, area, speed and pressure. Instant results with step-by-step working.
Open Meter Converter Convert meters to kilometers, centimeters, millimeters, feet, inches, miles, and 15+ more units instantly. See the conversion formula and a worked example.
Open Meter to Mile Converter Convert meters to miles instantly with the exact 1609.344 m factor. See miles, yards, and feet. Reverse conversion included. Formula and worked example shown.
Open Metric to Imperial Converter Convert metric to imperial units instantly: length (cm, m, km), weight (g, kg), temperature (degC), volume (L, mL), area, and speed. Shows all formulas step by step.
Open Metric to Inches Calculator Convert millimeters, centimeters, meters, or kilometers to inches instantly. Get decimal inches, fractional inches (1/16, 1/32, 1/64), plus the reverse conversion.
Open mg to lbs Converter Convert milligrams to pounds (and back) instantly. Shows pounds, ounces, grams and kilograms. Includes the formula, worked examples and a reference chart.
Open Micrometer Converter Convert micrometers to millimeters, nanometers, centimeters, meters, inches, feet, and more. Bidirectional: enter any unit and get all others instantly.
Open Micron to Mil Conversion Calculator Convert microns (micrometers) to mils or mils to microns instantly. See the formula, worked example, and a coating-thickness reference table.
Open Midsegment of a Trapezoid Calculator Calculate the midsegment (median) of a trapezoid from its two parallel bases, or reverse-solve to find a missing base. Step-by-step working and real formula.
Open Midsegment of a Triangle Calculator Calculate any midsegment of a triangle instantly. Enter a base length or vertex coordinates to find midsegment length, midpoint endpoints, and a step-by-step proof.
Open Mil Conversion Calculator Convert mils to mm, inches, micrometers, and more instantly. Includes formula, worked steps, and a reference table of common material thicknesses in mils.
Open Mil to Inch Conversion Calculator Convert mils (thou) to inches, millimeters, and microns instantly. See the formula, a step-by-step worked example, and a reference table of common material thicknesses.
Open Mile Conversion Calculator Convert miles to km, meters, feet, yards, inches, nautical miles, furlongs, and leagues instantly. Formula, step-by-step working, and a reference table included.
Open Millimeter Calculator Instantly convert millimeters to inches, centimeters, meters, feet, yards, micrometers, and mils. Bidirectional, exact, and free.
Open Minute Converter Convert minutes to seconds, hours, days, weeks, months, and years instantly. Enter any time unit and get the equivalent in minutes and all other units.
Open Minutes Between Two Times Calculator Calculate the exact minutes between any two times instantly. Get hours, minutes, seconds, decimal hours, and an overnight toggle. Free and accurate.
Open Minutes to Years Conversion Convert minutes to years instantly, with a full breakdown into years, months, weeks, days, hours, and seconds. Reverse conversion included.
Open Missing Side of a Right Triangle Calculator Find any missing side or angle of a right triangle instantly. Enter two known values (sides or an angle) to solve for the hypotenuse, legs, area, and perimeter.
Open Miter Angle Calculator Calculate miter and bevel saw angles for any corner, trim, frame, or crown molding. Equal or unequal widths, inside and outside corners, and compound cuts covered.
Open mL to cc Converter Convert milliliters to cubic centimeters instantly. 1 mL = 1 cc always. Covers medical doses, cooking, engine displacement, and lab volumes with a full reference table.
Open mL to lbs Conversion Convert milliliters to pounds for water, milk, flour, butter, oil, and any substance. Enter mL or lbs and get the instant reverse conversion with step-by-step math.
Open mL to oz Converter Convert milliliters to fluid ounces instantly. Shows US fl oz, UK (Imperial) fl oz, nutrition-label oz, liters, cups, tablespoons and teaspoons in one click.
Open mL to Tablespoon Converter Convert milliliters to tablespoons instantly. Choose US customary, US legal, UK/Imperial, metric, or Australian standards. Reverse tbsp-to-ml mode included.
Open mL to Teaspoon Converter Convert milliliters to teaspoons instantly. Supports US customary (4.929 ml), metric (5 ml), and UK imperial (5.919 ml) teaspoons with a full reference table.
Open MLVSS Calculator Calculate MLVSS from lab weights or MLSS concentration. Get VSS/MLSS ratio, MLVSS mass in the aeration tank, and system health interpretation for activated sludge.
Open MM (Millimeters) Calculator Convert millimeters (mm) to inches, centimeters, meters, feet, yards, kilometers and back. Instant results with step-by-step math and a reference table.
Open MM to Carat Conversion Calculator Convert millimeter dimensions to carat weight instantly. Supports 12 diamond shapes, girdle thickness, and 7 gemstone types with GIA-grounded formulas.
Open mm to Foot Converter Convert millimeters to feet instantly. Get decimal feet, feet and inches, and the reverse feet-to-mm result. Exact formula, worked steps, and a reference table.
Open mm to Inches Conversion Convert millimeters to inches instantly. Get decimal inches, fractional inches (1/8 to 1/64), feet and inches, plus a full reference chart for common mm values.
Open Millimeters to Kilometers Converter (mm to km) Convert millimeters to kilometers instantly. Enter any mm value to get the exact km result with the formula, worked example, conversion table, and reverse km-to-mm.
Open mm to m Conversion Calculator Convert millimetres to metres instantly. Enter any length in mm and get the result in metres, cm, km, inches, feet, yards and miles with full working shown.
Open mm to Ring Size Converter: All International Systems Convert millimeters to ring sizes across US/Canada, UK/Australia, EU/France, Germany, Switzerland and Japan. Enter diameter or circumference for instant results.
Open mmHg to atm Conversion Calculator Convert millimeters of mercury (mmHg) to atmospheres (atm) instantly. Includes the formula, reverse atm to mmHg conversion, kPa, Pa, psi and bar outputs.
Open Modulo in the Order of Operations Calculate modulo (remainder) step by step. See exactly where mod fits in PEMDAS order of operations, with proof, quotient, and negative-number support.
Open Modulo Operations with Negative Numbers Calculate modulo with negative numbers using all three conventions: truncated (C/Java/JS), floored (Python/Ruby), and Euclidean. Instant results with step-by-step math.
Open Modulo Operator: Practical Uses in Arithmetics Calculate the modulo (remainder) of any division instantly. Covers odd/even detection, clock arithmetic, unit conversion and cryptography uses with step-by-step work.
Open Money Counter Calculator Count any mix of bills, coins and rolled coins for USD, GBP, EUR, CAD, AUD or INR. Enter quantities by denomination and get an instant total with a full breakdown.
Open Money Per Hour Calculator Convert any salary to an hourly rate instantly. Enter annual, monthly, weekly, or daily pay plus hours worked to find your true money-per-hour figure.
Open Moneyline Odds Calculator Calculate moneyline bet payouts, profit, and implied probability. Convert American, decimal, and fractional odds with no-vig fair odds and a step-by-step breakdown.
Open Monthly Income Calculator Convert hourly, daily, weekly, bi-weekly, semi-monthly, quarterly, or annual pay into monthly income. Includes adjusted results for vacation days and holidays.
Open Months Between Two Dates Calculator Calculate the exact number of months between any two dates, with remaining days, total days, weeks, and years. Instant results, no rounding shortcuts.
Open MPa Conversion Calculator Convert megapascals (MPa) to psi, bar, kPa, Pa, atm, Torr, inHg and N/mm2 instantly. Reverse convert from any unit back to MPa. Includes reference table and worked examples.
Open MPa to PSI Conversion Convert megapascals to pounds per square inch (and back) instantly. Also outputs bar, kPa, atm and Pa. Includes step-by-step math, a common-pressures table and FAQs.
Open MPa to psig Conversion Calculator Convert MPa to psig instantly. Reverse psig-to-MPa mode, bar, kPa, atm and Pa outputs, step-by-step workings, and a common engineering pressure reference table.
Open Milliseconds to Seconds Converter Convert milliseconds to seconds instantly. Enter ms or seconds for bidirectional conversion, see the full formula, worked example, and a multi-unit breakdown.
Open Multiply Complex Numbers Calculator Multiply two complex numbers instantly. Enter rectangular (a+bi) or polar form, get the product in both forms with step-by-step working and modulus.
Open NaNoWriMo Calculator: Word Count Goal and Daily Target Track your NaNoWriMo progress, recalculate your daily word target, see your predicted finish date, and find out how many hours of writing time you need.
Open Natural Gas Converter Convert natural gas between BTU, MBTU, MMBtu, therm, dekatherm, MCF, CCF, kWh, MJ, GJ, LNG gallons, and CNG kg. Adjust heating value for your local gas spec.
Open New Year Countdown Calculator: Days, Hours and Minutes Until New Year Calculate days, hours, minutes and seconds until New Year's Day. See year-progress percentage, month-by-month milestone table, and the full step-by-step math.
Open New York Overtime Calculator Calculate your New York overtime pay instantly. Covers standard, residential, and farm worker rules, 2026 salary thresholds, and regional minimum wages.
Open nm to m Converter Convert nanometers to meters (or meters to nanometers) instantly. See the formula, a worked example, a scale reference table, and all related length units.
Open NPS Calculator Calculate your Net Promoter Score instantly. Enter promoter, passive and detractor counts, see your NPS with a score interpretation, breakdown and industry benchmarks.
Open Number of Days Calculator Count the exact number of days, weeks, months, and years between any two dates. Includes business days, weekends, and a full date breakdown. Free and instant.
Open Oblique Triangle Calculator Solve any oblique triangle from three known values. Covers SSS, SAS, SSA, ASA, and AAS with step-by-step working, area, inradius, circumradius, medians, and altitudes.
Open Obtuse Triangle Calculator Calculate every property of an obtuse triangle: all sides, angles, area, perimeter, altitudes, medians, inradius and circumradius. SSS, SAS, ASA, AAS and SSA modes.
Open Ohm's Law Current Calculator Calculate electrical current from voltage and resistance or from power and voltage. Solve all four Ohm's Law quantities with unit conversions and step-by-step working.
Open Ohm's Law Power Calculator Calculate voltage, current, resistance, and power using Ohm's Law. Enter any two values to instantly solve the other two with unit prefixes and step-by-step math.
Open Ohm's Law Resistance Calculator Enter any two of voltage, current, resistance, or power to solve for the other two. Covers all six Ohm's Law formulas with multi-prefix unit support.
Open Order from Least to Greatest Calculator Sort integers, decimals, fractions, mixed numbers, and percentages from least to greatest or greatest to least. Includes mean, median, and range.
Open Ordering Decimals Calculator Order up to 10 decimal numbers from smallest to largest or largest to smallest instantly. Shows aligned place-value comparison and step-by-step working.
Open Ordering Numbers Calculator Sort any list of numbers in ascending or descending order instantly. Get count, min, max, sum, mean, median, range, and standard deviation in one click.
Open Ounce to kg Converter Convert ounces to kilograms instantly. Supports avoirdupois and troy ounces, shows grams and pounds, includes a full conversion table and reverse kg to oz mode.
Open Ounces to Milliliters Converter Convert fluid ounces to milliliters instantly. Supports US and UK fluid ounces, reverse mL-to-oz conversion, and a full reference table for common measurements.
Open Overtime Paycheck Calculator Calculate your gross paycheck with regular, overtime, and double-time pay. Supports FLSA, California, and custom rules for hourly or salaried workers.
Open Oxygen Tank Duration Calculator: How Long Will Your O2 Last? Calculate how long your oxygen tank will last by cylinder size, pressure, and flow rate. Covers D, E, M, G, H/K cylinders with the AARC safe-residual formula.
Open oz to cc Converter Convert fluid ounces to cubic centimetres (cc) instantly. Supports US and UK/Imperial oz, reverse cc to oz, and shows the full formula and worked example.
Open Pa to psi Converter Convert pascals to psi and back. Supports Pa, kPa, MPa, bar, atm, mmHg, inHg, and more, with the formula, a worked example, and real-world pressure benchmarks.
Open Pallet Calculator Calculate how many boxes fit on a pallet, layers high (Hi), items per layer (Ti), stack height, total weight and pallet utilization. Metric and imperial.
Open Paper Quantity Converter Convert paper quantities instantly: sheets to reams, quires, bundles and bales. Supports long ream (500), short ream (480) and printer's ream (516).
Open Parallelogram Perimeter Calculator Calculate the perimeter of a parallelogram using sides, diagonals, or base-height-angle. Metric and imperial units, step-by-step math shown.
Open Parity Calculator Free parity calculator with three modes: check if an integer is even or odd, generate a binary parity bit for error detection, and verify a received binary message.
Open Pascal Conversion Calculator Convert pascals to bar, kPa, MPa, psi, atm, Torr, mmHg, inHg, mbar, and 10+ other pressure units instantly. Enter any unit to see all conversions at once.
Open Passer Rating Calculator Calculate NFL, NCAA or CFL passer rating instantly. Enter attempts, completions, yards, touchdowns and interceptions to get a full breakdown of all four formula components.
Open Passive House Savings Calculator Compare heating costs and payback periods for regular, energy-efficient, and passive houses. Enter floor area, build cost, and energy price to see lifetime savings.
Open Pay Gap Calculator Calculate the gender (or any group) pay gap in seconds. Get the mean gap, median gap, per-dollar ratio, and equalised salary with step-by-step working.
Open Pendulum Frequency Calculator Calculate pendulum frequency, period, length, or gravity. Small-angle and nonlinear correction, metric and imperial units, step-by-step working shown.
Open Pendulum Period Calculator Calculate the period and frequency of a simple pendulum from length and gravity. Supports large-angle correction, reverse solve, and gravity presets for any planet.
Open Perimeter of a Quadrilateral Calculator Find the perimeter of any quadrilateral by entering four side lengths or four vertex coordinates. Supports metric and imperial, shows full step-by-step working.
Open Perimeter of a Rectangle Calculator Calculate the perimeter of any rectangle from length and width, or reverse-solve for a missing side from the perimeter. Shows the formula and all steps.
Open Perimeter of a Rectangle with Given Area Calculator Find the perimeter of a rectangle from its area and one side length. Instant results with step-by-step working, diagonal, and minimum perimeter insight.
Open Perimeter of a Right Triangle Calculator Calculate the perimeter of a right triangle from two legs, or one leg and the hypotenuse. Get area, altitudes, semiperimeter, and step-by-step working.
Open Perimeter of a Sector Calculator Calculate the perimeter of a sector instantly. Enter radius and central angle in degrees or radians. Includes arc length, sector area, and step-by-step working.
Open Permutation with Repetition Calculator Calculate permutations with or without repetition instantly. Enter n objects and r positions, get nPr, step-by-step working, a growth chart, and real-world examples.
Open Permutation Without Repetition Calculator Calculate permutations without repetition P(n,r) instantly. See the step-by-step factorial formula, a comparison table, and worked examples for any n and r.
Open PERT Calculator Free PERT calculator for project managers. Compute expected time, standard deviation, variance, and on-time completion probability for up to 5 critical-path tasks.
Open Pet Sitter Rates Calculator Calculate pet sitter rates instantly. Enter service type, pet count, visit quantity, and optional add-ons to get a full booking quote with market comparison.
Open Pie Chart Angle Calculator Calculate pie chart slice angles in degrees and percentages for up to 8 data groups. Shows your work step by step and reverse-solves angle to percentage.
Open Pie Chart Percentage Calculator Convert any set of values into pie chart percentages and central angles. Enter up to 8 categories for a live donut chart, worked steps, and a breakdown table.
Open Pints to Cups Converter Convert pints to cups instantly. Supports US pints, UK pints, US cups, UK cups and metric cups. Includes a reverse cups-to-pints mode and a full reference table.
Open Pints to Gallons Converter Convert pints to gallons instantly for US or UK (imperial) measurements. Get the result both ways, see the formula, litres equivalent, and a full reference table.
Open Pivot Point Calculator Calculate pivot points for any market with five methods: Standard, Fibonacci, Woodie, Camarilla, and DeMark. Get support and resistance levels instantly.
Open Pixel Aspect Ratio Calculator Calculate aspect ratio from pixel dimensions, find missing width or height from a ratio, and resize any image or video while keeping it perfectly proportional.
Open Pizza Tip Calculator Calculate exactly how much to tip your pizza delivery driver. Adjusts for service quality, weather, distance, peak hours, group size, and bill splitting.
Open D&D 5e Point Buy Calculator Free D&D 5e point buy calculator: track your 27-point budget, see ability modifiers instantly, and compare your build to the standard array.
Open Pokemon GO Weight Loss Calculator Calculate calories burned playing Pokemon GO, fat loss from hatching eggs, and how many sessions to reach your goal. Free, instant results.
Open Poker EV Calculator Calculate the expected value of any poker decision. Enter win probability, pot size, and bet to find break-even equity, EV in dollars or big blinds, and semi-bluff EV.
Open Poker Odds Calculator Calculate poker pot odds, outs-to-equity with the Rule of 2 & 4, implied odds, and expected value. Instant results with step-by-step math for Texas Hold'em.
Open Polar Form Calculator Convert complex numbers between rectangular (a + bi) and polar form. Get magnitude, angle in degrees or radians, and exponential and trig forms with worked steps.
Open Polar to Cartesian Coordinates Calculator Convert polar coordinates (r, theta) to Cartesian (x, y) instantly - or reverse from Cartesian to polar. Choose degrees or radians. Full worked steps included.
Open Polygon Angle Calculator Calculate interior angles, exterior angles, sum of angles, central angle, and diagonals for any regular polygon. Solve forward from sides or reverse from a known angle.
Open Pool Table Room Size Calculator Find the minimum room size for any pool table in seconds. Enter your table type and cue length to get the exact length and width you need, in feet or metres.
Open Portrait Aspect Ratio Calculator Calculate simplified portrait aspect ratios, match social media presets, and find the exact pixel dimensions needed to resize any portrait image or vertical video.
Open Possible Combinations Calculator Calculate possible combinations (nCr) with or without repetition, plus permutations. Shows the formula, step-by-step working, and a breakdown visual.
Open Post Hole Concrete Calculator Calculate concrete volume and bag count for post holes in metric or imperial. Supports round and square posts, multiple posts, and 40/60/80 lb bag sizes.
Open Pounds to lbs Converter Convert pounds (lb) to kilograms, ounces, grams, stone, metric tons, grains, carats, and more. Instant multi-unit results with a worked example and formula.
Open Pounds to Stone Converter Convert pounds to stone instantly - and stone back to pounds. See the whole-stone and remaining-pounds split, the decimal stone value, and a full reference chart.
Open Power Function Calculator Calculate b^x instantly. Handles negative bases, fractional exponents, and e as base. Reverse-solve for base or exponent. Steps and rules included.
Open Power of 10 Calculator Calculate 10 raised to any exponent (positive, negative, or decimal), convert to scientific notation, find the inverse log, and explore the full metric prefix table.
Open Power of 2 Calculator Calculate 2 raised to any exponent instantly. Get 2^n, its reciprocal 1/2^n, log base 2, and the computing context for landmark values like 1 KiB, 1 MiB, and 1 GiB.
Open PPM to mg/L Converter Convert parts per million (ppm) to milligrams per liter (mg/L) for any solution. Choose a density preset or enter custom density, get molarity and more.
Open Pressure Unit Conversion Calculator Convert any pressure unit instantly: Pa, kPa, MPa, bar, mbar, psi, atm, Torr, mmHg and inHg. See the formula, worked steps, and a real-world reference table.
Open Price Per Linear Foot Calculator Calculate price per linear foot instantly. Compare two options side by side, add a waste factor, estimate total project cost, and find out your budget buys.
Open Price per Ounce Calculator Calculate price per ounce instantly. Compare two products, reverse-solve a target price, and see cost per pound and per 100 g side by side.
Open Price per Pound Calculator Calculate the price per pound for any product and compare two items side by side to find the better deal. Supports pounds, ounces, kilograms and grams.
Open Price per Round Calculator Compare two ammo deals side by side. Enter box price and round count to find cost per round, total savings, and bulk vs. single-box breakeven. Free and instant.
Open Price Per Share Calculator Calculate price per share from market cap and shares outstanding, or use the Gordon Growth Model. Compare two stocks side by side. Free, instant results.
Open Price Per Square Inch Calculator Calculate cost per square inch for any item and compare two options side by side. Enter flat area or length and width. Supports sq in, sq ft, sq cm, and sq m.
Open Price Per Unit Calculator Compare price per unit for two products across weight, volume, count, area, length, or time. Find the best deal and see your savings instantly.
Open Price per Weight Calculator Find the cheapest product by weight instantly. Enter price and weight for up to 3 items, choose metric or imperial units, and see the cost per kg, lb, g, or oz side by side.
Open Privacy Fence Calculator Estimate your privacy fence cost, post count, rail count, and pickets by length, height, and material type. Includes gate costs and a full project breakdown.
Open Protein Molecular Weight Calculator Calculate protein molecular weight from an amino acid sequence in seconds. Get mass in Daltons and kDa, extinction coefficient, and residue breakdown. Supports FASTA.
Open PSI Converter: Convert PSI to Bar, kPa, atm, mmHg and More Convert PSI to bar, kPa, MPa, Pa, atm, mmHg, inHg and psf instantly. Enter any pressure unit and get every equivalent in real time, with the formula and worked steps.
Open PSI to ATM Conversion Calculator Convert psi to atm or atm to psi instantly. See the result in pascals, kilopascals, and bar too. Exact NIST conversion factor, worked steps, and real-world examples.
Open PSI to Inches of Water Conversion Calculator Convert PSI to inches of water (inH2O) instantly, or reverse from inH2O to PSI. Choose 4 C or 60 F water reference, get Pa and kPa outputs with full steps.
Open PX to EM Converter Convert pixels to em, rem, pt, or percent instantly. Set a custom base font size, see the full worked formula, and explore a reference table of common conversions.
Open Pythagoras Triangle Calculator Solve for any side of a right triangle using the Pythagorean theorem. Get area, perimeter, angles, and altitude with metric or imperial units and step-by-step working.
Open Quantity Converter Convert any quantity between units, pairs, half dozens, dozens, baker's dozens, scores, grosses, and great grosses. Instant bidirectional results with worked steps.
Open Quantum Number Calculator Find all four quantum numbers for any electron shell. Enter n (and l) to see valid l, ml, ms values, orbital counts, max electrons, and a combination table.
Open Quarantine Food Calculator Calculate exactly how much food your household needs for a quarantine period. Covers fruits, vegetables, perishables, pantry staples and canned goods by number of days.
Open Quarter Circle Area Calculator Calculate the area, arc length, perimeter, and chord of a quarter circle from radius or diameter. Metric and imperial units, with step-by-step working.
Open Quarter Circle Calculator Calculate the area, arc length, perimeter, chord, and external area of a quarter circle. Enter the radius or diameter and get all properties instantly.
Open Quartic Regression Calculator Fit a quartic (4th-degree) regression curve to your data. Enter x,y pairs to get all five coefficients, R-squared, residual standard error, and a fitted curve chart.
Open Quarts to Cups Converter Convert quarts to cups instantly for US or UK measurements. See the formula, a step-by-step breakdown, equivalent fluid ounces and milliliters, and a full conversion table.
Open Queueing Theory Calculator Calculate queue performance metrics for M/M/1 and M/M/c models: utilization, average wait time, queue length, P0, Erlang C, and Little's Law breakdowns.
Open Radians to Degrees Converter Convert radians to degrees (and degrees back to radians) instantly. Shows the step-by-step formula, worked example, and a reference table of common angles.
Open Radiation Unit Converter: Gy, Sv, rad, rem, Bq, Ci, R Convert radiation units: absorbed dose (Gy/rad), equivalent dose (Sv/rem), radioactivity (Bq/Ci), and exposure (R/C/kg). Includes ICRP radiation weighting factors.
Open Radius of a Circle Calculator Find the radius of a circle from its area, diameter, circumference, or sector, and get diameter, area, circumference, and arc length with step-by-step workings.
Open Radius of a Cone Calculator Calculate the radius of a cone from height and slant height, volume, lateral surface area, base area, or total surface area. Shows all cone dimensions instantly.
Open Radius of a Cylinder Calculator Find the radius of a cylinder from volume, height, lateral area, total surface area, or diameter. Instant results in metric and imperial units.
Open Radius of a Sphere Calculator Find the radius of any sphere from its diameter, circumference, surface area, volume, or surface-to-volume ratio. Instant results with worked steps.
Open Ratio of 2 Numbers Calculator Simplify, scale, or solve a ratio of two numbers instantly. Shows the simplified form, 1:n and n:1 forms, equivalent ratios, fraction, decimal, and percentages.
Open Ratio of 3 Numbers Calculator Simplify a 3-part ratio, scale it by any factor, divide an amount in a ratio, or find the GCF. Instant results with step-by-step working shown.
Open Rational Exponents Calculator Calculate any rational exponent b^(p/q) instantly. See the nth-root equivalent, decimal result, step-by-step work, negative exponents, and worked examples.
Open RC Filter Calculator Calculate the cutoff frequency, time constant, impedance, phase shift, and voltage gain of any RC low-pass or high-pass filter. Reverse-solve for R or C.
Open Reaction Time Calculator Calculate reaction time from a ruler drop test, Hick's Law for choice tasks, and driving reaction distance. See your performance rating and the math behind it.
Open Recruitment Process Duration Calculator Calculate total recruitment process duration by stage: sourcing, screening, interviews, offer, and acceptance. Compare against industry benchmarks instantly.
Open Rectangle Diagonal Angle Calculator Calculate all angles formed by rectangle diagonals: corner angles, intersection angles, diagonal length, area and perimeter. Instant results with step-by-step working.
Open Rectangle Scale Factor Calculator Calculate the scale factor between two rectangles. Find the linear scale factor, area scale factor, scaled dimensions, and area change from any two rectangles.
Open Rectangular Pyramid Volume Calculator Calculate the volume, total surface area, lateral surface area, and slant heights of a rectangular pyramid instantly. Metric and imperial, with step-by-step working.
Open Rectangular to Polar Coordinates Calculator Convert rectangular (x, y) coordinates to polar (r, theta) instantly. Choose degrees or radians, see quadrant, full step-by-step math, and the inverse conversion.
Open Relative Strength Index (RSI) Calculator Calculate the Relative Strength Index (RSI) from closing prices. Enter up to 50 prices and a period to get the RSI, RS ratio, average gain and loss, and zone.
Open REM Sleep Calculator Find the ideal bedtime or wake-up time based on 90-minute sleep cycles. See REM, deep sleep, and total sleep breakdowns with age-based recommendations.
Open Remote vs. On-Location Workers Calculator Compare the true annual cost of remote versus on-location employees. Enter headcount, office lease, allowances, and equipment to see side-by-side totals and savings.
Open Retirement Countdown Calculator Count exactly how many days, weeks, months, and working days remain until you retire. Track Social Security, Medicare, and RMD milestones in one free calculator.
Open Right Square Pyramid Calculator Calculate the volume, total surface area, lateral area, base area, slant height, and lateral edge of a right square pyramid. Enter any two dimensions to solve.
Open Right Trapezoid Area Calculator Calculate the area, perimeter, slant side, midsegment, and angles of a right trapezoid instantly. Supports metric and imperial units with a full worked solution.
Open Right Trapezoid Calculator Calculate the area, perimeter, diagonals, oblique leg, midsegment, and base angle of a right trapezoid. Enter any two sides plus height to solve the shape instantly.
Open Right Triangle Trigonometry Calculator Solve any right triangle instantly. Enter two known values to find all sides, angles, altitude, area, and perimeter. Degrees or radians, with full step-by-step trig.
Open Root Mean Square Speed Calculator for Ideal Gas Calculate the root mean square speed of any ideal gas from temperature and molar mass, with preset gases, unit switching, mean speed, and most probable speed.
Open Round Pen Calculator Calculate round pen circumference, area, panel count, post count and footing volume from the diameter and panel length. Supports metric and imperial units.
Open Round to the Nearest Cent Calculator Round any dollar amount to the nearest cent, nickel, dime, quarter, or dollar. Six rounding modes including banker's rounding. Instant with step-by-step math.
Open Round to the Nearest Hundred Calculator Round any number to the nearest hundred instantly. Choose half-up, half-down, half-even, ceiling, floor, or truncate. See the step-by-step working.
Open Round to the Nearest Hundredth Calculator Round any number to the nearest hundredth (2 decimal places) instantly. Choose your rounding method, see the step-by-step work, and compare 8 rounding modes.
Open Round to the Nearest Integer Calculator Round any decimal to the nearest integer instantly. Choose from 7 rounding modes: half-up, half-down, half-even, half-odd, half-away-from-zero, floor, and ceiling.
Open Round to the Nearest Penny Calculator Round any amount to the nearest penny, nickel, dime, quarter, or dollar using standard, half-even (banker's), ceiling, floor, or truncate rounding. See the math instantly.
Open Round to the Nearest Ten Calculator Round any number to the nearest 10. Choose half-up, half-down, half-even, or truncate mode, see the step-by-step working, and compare rounding across places.
Open Round to the Nearest Tenth Calculator Round any number to the nearest tenth, hundredth, thousandth, or whole number. Choose your rounding method, see the step-by-step logic, and get instant results.
Open Round to the Nearest Thousandth Calculator Round any number to the nearest thousandth (3 decimal places) instantly. Choose your rounding mode, see the digit-by-digit steps, and learn the rules.
Open Rounds per Minute Calculator: RPM, Cycle Time and Rate of Fire Calculate rounds per minute from rounds fired and time, or find cycle time from RPM. Includes rate of fire by weapon class, worked steps, and a reference table.
Open Salary Calculator With Overtime Calculate your salary with overtime pay: enter your hourly rate, standard hours, pay period and overtime hours to get regular pay, overtime pay and annual earnings.
Open Salt Dough Calculator Scale any salt dough recipe by flour, salt, or water amount. Choose from 5 recipe variants, switch metric or imperial, and get baking time, yield, and cost instantly.
Open SAS Triangle Calculator Solve any SAS triangle instantly: enter two sides and the included angle to get the third side, all angles, area, perimeter, altitudes, medians and circumradius.
Open Scientific Notation Converter Convert any number to scientific, E-notation, and engineering notation instantly. Add, subtract, multiply, or divide in scientific notation with step-by-step working.
Open Screen Ratio Calculator Calculate screen aspect ratio from width and height, find the nearest standard ratio, scale to new dimensions, and compute diagonal size. Supports 16:9, 4:3, and 21:9.
Open Seconds Converter Convert seconds to nanoseconds, milliseconds, minutes, hours, days, weeks, months and years instantly. Reverse conversion from any time unit back to seconds.
Open Seconds to Days Converter Convert seconds to days instantly. Get the full breakdown into days, hours, minutes and leftover seconds, plus reverse conversion from days back to seconds.
Open Seconds to Hours Converter Convert seconds to hours instantly. Get the result as decimal hours and in hours, minutes, and seconds (H:MM:SS) with a step-by-step breakdown.
Open Seconds to Years Converter Convert seconds to years instantly and see the full breakdown: years, days, hours, minutes and seconds left over. Reverse-solve from years back to seconds.
Open Sensitivity Calculator Free sensitivity calculator for diagnostic tests. Compute specificity, PPV, NPV, likelihood ratios, accuracy, Youden index and more from a 2x2 confusion matrix.
Open Shannon Diversity Index Calculator Calculate the Shannon Diversity Index (H), Pielou evenness, and species richness for up to 10 species. Step-by-step math, rank-abundance chart, and H interpretation.
Open Shannon Entropy Calculator Calculate Shannon entropy from a probability distribution or text string in bits, nats, or hartleys. Get efficiency, redundancy, perplexity and step-by-step breakdown.
Open Similar Right Triangles Calculator Solve similar right triangles instantly. Find the geometric mean altitude, legs, scale factor, missing sides, and angles - with full step-by-step working.
Open Simplify Ratio Calculator Simplify any ratio instantly - whole numbers, decimals, fractions, or mixed numbers. Supports 2- and 3-part ratios with step-by-step GCD working shown.
Open Sin-1 Calculator (Arcsin) Calculate sin-1(x), the inverse sine (arcsin), instantly. Enter any value from -1 to 1 and get the angle in degrees and radians with step-by-step working.
Open Sin 2 Theta Calculator Calculate sin(2θ) instantly from an angle, from sin and cos values, or from tan(θ). Get cos(2θ), tan(2θ), the full double angle workings, and a reference table.
Open Sin Degrees Calculator Calculate the sine of any angle in degrees or radians instantly. Includes inverse sine, exact values for special angles, quadrant analysis, and a worked steps panel.
Open Sin Theta Calculator Calculate sin(θ) instantly for any angle in degrees, radians, or pi-radians. Includes inverse sine, unit circle visual, step-by-step working, and a reference table.
Open Sine Cosine Tangent Calculator Calculate sine, cosine, and tangent for any angle in degrees, radians, or gradians. Get all six trig functions, inverse values, and step-by-step working.
Open Sine Function Calculator Calculate sin(x) instantly in degrees or radians, with the exact fraction, inverse arcsine, cosecant, unit-circle reading and a full sine wave chart.
Open Law of Sines Calculator Law of sines triangle solver. Enter AAS, ASA, or SSA values to find sides, angles, area, perimeter, circumradius, and inradius. Ambiguous case handled automatically.
Open Sinh Calculator - Hyperbolic Sine Calculate sinh(x) instantly. Get all six hyperbolic functions, the inverse arsinh, step-by-step workings, identities, and an interactive curve - all in one free tool.
Open Ski Size Calculator Find your ideal ski length by height, weight, ability level, skiing style, and ski type. Get a recommended range in centimetres or inches, instantly.
Open Slant Height of a Cone Calculator Calculate the slant height of a cone from radius and height, or solve for any two unknowns. Get volume, surface area, and all angles instantly.
Open Sleep Cycle Calculator Find optimal bedtimes and wake-up times based on 90-minute sleep cycles. Choose your mode, enter a time, and see schedules for 4, 5, and 6 complete cycles.
Open Sleep Time Calculator Calculate the best time to go to bed or wake up based on 90-minute sleep cycles. See ideal bedtimes, wake times, sleep debt, and age-based recommendations.
Open Smog Calculator Convert air pollution (PM2.5) into AQI, daily cigarette equivalents, and annual health impact. See your exposure risk based on time spent outdoors.
Open Solve Similar Triangles Calculator Solve similar triangles instantly. Enter known sides, find missing lengths, calculate the scale factor, check SSS/SAS/AA similarity, and see step-by-step working.
Open Completing the Square Calculator Solve any quadratic equation by completing the square. Enter a, b, c and get the vertex form, discriminant, both roots, and a full step-by-step walkthrough.
Open Specificity Calculator Calculate specificity, sensitivity, PPV, NPV, likelihood ratios, accuracy, Youden's J and F1 score from a 2x2 confusion matrix. Free, instant, with step-by-step math.
Open Speed Conversion Calculator Convert speed between mph, km/h, m/s, knots, Mach, ft/s, ft/min and km/s instantly. See all units at once, with the conversion math shown step by step.
Open Sphere Density Calculator Calculate the density, mass, volume, radius, surface area and diameter of any sphere. Solve any variable from the others with metric or imperial units.
Open Square Feet Converter Convert square feet to square meters, acres, square yards, hectares, square inches, or kilometers instantly. Bidirectional - convert any area unit to square feet too.
Open Square Feet of a Triangle Calculator Calculate the square feet of any triangle using base and height, three sides (Heron's), SAS, or ASA. Switch units, see your work, and get the cost estimate instantly.
Open Square Feet to Acres Calculator Convert square feet to acres instantly - and back again. See your area in 6 units, get a real-world size comparison, and learn the formula with a worked example.
Open Square Footage of a Circle Calculator Calculate the square footage of any circle from radius, diameter or circumference. Switch units, add a price per sq ft, and see the full step-by-step working.
Open Square Inches of a Circle Calculator Find the area of a circle in square inches from radius, diameter, or circumference. Switch units, reverse-solve from area, and see step-by-step working.
Open Square Meter Converter Convert square meters to square feet, acres, hectares, square inches, yards, kilometers and more. Instant two-way area unit converter with a full conversion table.
Open Square Pyramid Calculator Calculate the volume, surface area, slant height, lateral edge, and face angle of any square pyramid. Metric and imperial, with step-by-step solution.
Open Square Pyramid Volume Calculator Calculate volume, slant height, surface area, and lateral edge of a square pyramid. Seven solve modes, metric/imperial units, step-by-step working included.
Open SSA Triangle Calculator: Ambiguous Case Solver Solve SSA triangles (side-side-angle) instantly. Handles the ambiguous case: finds 0, 1, or 2 valid triangles with all sides, angles, area, and perimeter shown step by step.
Open Standard Equation of a Circle Calculator Convert a circle between standard, general, and parametric forms. Enter center and radius or general form coefficients to get area, circumference, and intercepts.
Open Standard Form to General Form of a Circle Calculator Convert a circle equation from standard form (x-h)^2+(y-k)^2=r^2 to general form x^2+y^2+Dx+Ey+F=0 instantly. Shows every algebraic step.
Open Standard Notation Calculator Convert between scientific notation, E-notation, engineering notation and standard decimal form instantly. Includes step-by-step working and SI prefix lookup.
Open Steak Cook Time Calculator Find the exact cook time for your steak by thickness, doneness, cut, and cooking method. Get pull temperature, resting time, and a step-by-step guide.
Open Stone to kg Converter Convert stone to kg instantly with the exact formula. Enter stone and optional pounds, or switch to kg and get stone back. Full conversion table and worked example included.
Open Stone to Lbs Converter Convert stone to lbs and kg instantly. Enter stone or stone + pounds, get exact pounds, kilograms, and ounces. Includes a full conversion table and reverse lookup.
Open Sulfur Calculator Calculate molecular SO2 in wine from free SO2 and pH, or find the elemental sulfur needed to lower soil pH. Instant results with step-by-step math.
Open Sunrise & Sunset Calculator Calculate exact sunrise, sunset, solar noon, civil dawn, nautical dawn, and astronomical dawn for any location and date. Shows daylight hours and dawn type breakdown.
Open Sunset Calculator Calculate exact sunset, sunrise, solar noon, golden hour, civil twilight, nautical twilight, and astronomical twilight for any location and date.
Open Surface Area of a Cone Calculator Calculate the total, lateral (curved) and base surface area of a cone. Enter radius and height or slant height. Metric and imperial units, step-by-step working shown.
Open Surface Area of a Cylinder Calculator Calculate the total, lateral (curved), and base surface area of a cylinder instantly. Supports metric and imperial units with a step-by-step solution.
Open Surface Area of a Rectangle Calculator Calculate the surface area, perimeter, and diagonal of any rectangle instantly. Supports metric and imperial units with a step-by-step breakdown.
Open Surface Area of a Rectangular Prism Calculator Calculate the total surface area, lateral surface area, base area, volume, and space diagonal of any rectangular prism. Metric and imperial units supported.
Open Surface Area of a Rectangular Pyramid Calculator Calculate the total, base, and lateral surface area of a rectangular pyramid instantly. Shows slant heights, face areas, volume, edge length, and step-by-step working.
Open Surface Area of a Square Pyramid Calculator Calculate the total surface area, lateral surface area, base area, and face area of a square pyramid. Choose metric or imperial units and see the full working.
Open Surface Tension Calculator Calculate surface tension, capillary rise height, Young-Laplace pressure difference, and force on a wire. Covers water, mercury, ethanol, and custom liquids.
Open Tan-1 Calculator (Arctan) Calculate tan-1(x) instantly. Get the inverse tangent in degrees, radians, and DMS with step-by-step working, an arctan curve, and a reference table of common values.
Open Tan Inverse Calculator (arctan) Find arctan in degrees, radians, gradians, and pi fractions. Enter a tangent value or triangle sides for instant inverse tangent results with step-by-step work shown.
Open Tangent Angle Calculator Calculate tan(x) for any angle in degrees or radians. Includes arctangent reverse-solve, step-by-step working, and a full tangent reference table.
Open Tangent Ratio Calculator Calculate the tangent ratio from opposite and adjacent sides, or reverse-solve for a side from any angle. Shows all six trig ratios with a worked step panel.
Open Tanh Calculator - Hyperbolic Tangent Calculate the hyperbolic tangent tanh(x) instantly. Enter any real number to get tanh(x), related hyperbolic functions sinh and cosh, and full step-by-step working.
Open Tablespoon to mL Converter Convert tablespoons to milliliters instantly. Covers US, metric and UK/Imperial standards with the exact conversion factor, worked steps, and a reference chart.
Open Temperature Conversion Calculator Convert temperature instantly between Celsius, Fahrenheit, Kelvin, Rankine and Reaumur. See the step-by-step formula and a reference table of key fixed points.
Open Tennis Ball Usage Calculator Calculate how many tennis balls you need for practice, matches, or a season. Get cans needed, weekly cost, and a session-by-session schedule. Free and instant.
Open Texas Overtime Calculator Calculate Texas overtime pay instantly. Enter your hourly rate and hours to see gross pay, FICA, federal tax, and net take-home pay. Texas has no state income tax.
Open Theta Calculator Enter any angle theta in degrees, radians, or pi-radians to instantly get sin, cos, tan, csc, sec, cot, inverse trig values, and double-angle identities.
Open Third Quartile Calculator: Q3, IQR, and Five-Number Summary Calculate Q3, Q1, median, IQR, and the five-number summary from any dataset. Three quartile methods, outlier detection, and step-by-step work shown.
Open TikTok Time Alternatives Calculator Enter how long you scroll TikTok each day and see how many books you could read, calories you could burn, and language levels you could reach with that time instead.
Open Time in Between Calculator: Hours, Minutes and Seconds Between Two Times Calculate the exact time between two times in hours, minutes, and seconds. Handles same-day and overnight spans. Free, instant, no sign-up required.
Open Time of Death Calculator Estimate time since death using the Henssge nomogram or Glaister equation. Enter body temperature, ambient temperature, and body weight to get a forensic PMI estimate.
Open Time to Hours Calculator Convert any combination of days, hours, minutes, and seconds into decimal hours instantly. See the step-by-step math and a full time-unit reference table.
Open Time Until Calculator Find exactly how long until any date or event: years, months, days, hours, minutes and seconds. Use quick-picks for New Year, Christmas, Halloween and more.
Open Tip from Net Price Calculator Calculate the tip on the net (pre-tax) price of your bill. Enter the gross total, tax rate, and tip percentage to get the tip, total, and per-person share instantly.
Open Trapezoid Angle Calculator: Find All Four Interior Angles Find all four interior angles of any trapezoid. Enter two known angles, or use base lengths, leg lengths, and height. Instant results with step-by-step working.
Open Trapezoid Height Calculator Calculate the height of a trapezoid from a leg and angle, two bases and area, or both legs and angles. Shows every step and a labeled diagram.
Open Travel Expenses Calculator Calculate the full cost of any trip: flights, accommodation, meals, activities and extras. Get a per-day and per-person breakdown instantly.
Open Triangle Congruence Calculator Check whether two triangles are congruent by SSS, SAS, ASA, AAS or HL. Instantly solves all missing sides, angles, area, perimeter, inradius and circumradius.
Open Triangle Degree Calculator Find all angles, sides, area, perimeter, and radii of any triangle. Supports SSS, SAS, ASA, AAS, two-angle, and right triangle modes. Step-by-step solutions shown.
Open Triangle Length Calculator Solve any triangle by entering its sides and angles. Calculates missing sides, angles, area, perimeter, altitudes, and circumradius instantly with step-by-step working.
Open Triangle Proportionality Theorem Calculator Solve for any missing segment using the triangle proportionality theorem. Enter any three of AD, DB, AE, EC and get the fourth instantly, with steps and a diagram.
Open Triangle Ratio Calculator Find all three angles of a triangle from any angle ratio (a:b:c). Optionally enter a known side to get all side lengths, area, and perimeter instantly.
Open Triangle Scale Factor Calculator Find the scale factor between two similar triangles, check similarity, calculate missing sides, and see how areas and perimeters scale. Free, instant results.
Open Triangle Side and Angle Calculator Solve any triangle from sides and angles. Enter SSS, SAS, ASA, AAS, or SSA values to get all sides, angles, area, perimeter, inradius, circumradius, and medians.
Open Triangle Side Calculator Find any missing triangle side or angle instantly. Covers right triangles, SAS, SSS, ASA, AAS, and SSA with step-by-step working, area, perimeter, and circle radii.
Open Triangle Similarity Calculator Check if two triangles are similar using AA, SAS, or SSS criteria. Instantly find the scale factor, missing sides, perimeters, and areas with step-by-step working.
Open Triangle Slope Calculator: Rise, Run, Angle, and Percentage Calculate slope from rise and run, or from two coordinate points, or from an angle. Get slope ratio, angle, percentage grade, and a step-by-step solution instantly.
Open Triangle Sum Theorem Calculator Use the triangle sum theorem to find a missing interior angle. Enter two known angles in degrees or radians and get the third angle, exterior angles, and triangle type.
Open Triangle Vertices Calculator Enter three coordinate vertices and instantly get area, perimeter, angles, side lengths, centroid, circumcenter, incenter, orthocenter, inradius, and circumradius.
Open Triangular Pyramid Volume Calculator Calculate the volume of a triangular pyramid. Enter base triangle dimensions and pyramid height to get volume, base area, and slant height with step-by-step working.
Open Trig Calculator Calculate all six trig functions (sin, cos, tan, csc, sec, cot) and inverses in degrees, radians, or gradians. Includes a right-triangle solver and step-by-step work.
Open Trig Degree Calculator Find all six trig function values (sin, cos, tan, cot, sec, csc) for any angle in degrees. Includes quadrant info, step-by-step work, and a special-angle reference table.
Open Trig Function Calculator Calculate all six trigonometric functions - sin, cos, tan, csc, sec, and cot - for any angle in degrees, radians, or gradians. Includes inverse trig and worked steps.
Open Trig Triangle Calculator Solve any triangle from two known values. Enter sides and angles to get all missing measurements, area, perimeter, altitudes, medians, inradius, and circumradius instantly.
Open TRIR Calculator Calculate your OSHA TRIR, DART rate, and DAFW rate instantly. Enter recordable incidents and hours worked, then compare against 2024 BLS industry benchmarks.
Open Trump's Wall Cost Calculator: Estimate the US-Mexico Border Wall Calculate the US-Mexico border wall cost by length, height, material, guards, and lifetime. Full construction breakdown with official government estimates.
Open Truncated Cone Calculator Calculate the volume, total surface area, lateral surface area, and slant height of a truncated cone (frustum) in metric or imperial units. Shows full working steps.
Open Truncated Cone Volume Calculator Calculate truncated cone (frustum) volume, lateral and total surface area, and slant height, with step-by-step working and metric or imperial units.
Open Teaspoons to Grams Converter Convert teaspoons to grams for 60+ cooking ingredients including flour, sugar, salt, butter and honey. Reverse mode converts grams back to teaspoons. Free online tool.
Open Teaspoon to ml Converter Convert teaspoons to millilitres instantly. Supports US, metric, and imperial teaspoons. Includes reverse ml-to-tsp mode, a cooking reference table, and the formula.
Open Twin Pregnancy Weight Gain Calculator Calculate healthy weight gain for a twin pregnancy by week. Uses official IOM guidelines adjusted for your pre-pregnancy BMI, with trimester targets and a week-by-week chart.
Open Two Dice Probability Calculator Calculate the exact probability of any two-dice outcome: sum equals, at least, at most, doubles, and more. Works for d4, d6, d8, d10, d12, and d20.
Open Ugly Duckling Theorem Calculator Calculate total predicates, shared predicates, and Hamming distance for any object set using Watanabe's Ugly Duckling Theorem. Step-by-step math included.
Open UK to US Shoe Size Converter Convert UK shoe sizes to US, EU, and Japan sizes for men and women instantly. Includes full conversion tables, the barleycorn formula, and a reverse mode.
Open Upper Fence Calculator Calculate the upper and lower fences for any dataset using the IQR method. Enter raw data or supply Q1 and Q3 directly, adjust the multiplier, and identify outliers instantly.
Open US to EU Shoe Size Converter Convert US shoe sizes to EU, UK, and CM instantly. Includes men's and women's charts, foot length in inches and centimeters, and a full reference table.
Open US to UK Shoe Size Converter Convert US shoe sizes to UK, EU, and foot length for men, women, and kids. Instant results with conversion tables, formulas, and worked examples.
Open VA Disability Calculator Find your 2026 VA combined disability rating and monthly pay. VA whole-person formula with bilateral factor, TDIU check, and dependent pay adjustments included.
Open Vacation Countdown Calculator: Days Until Your Trip Count down the days, hours, and minutes until your vacation. Enter departure and return dates to see days remaining, weeks, workdays off, and total trip length.
Open Vinyl Fence Cost Calculator Estimate vinyl fence installation cost by linear footage, style, height, gates, region, and extras. Get a full material/labor breakdown instantly - free online tool.
Open Volume of a Cube Calculator Calculate cube volume from side length, face diagonal, space diagonal, or surface area. Instant metric and imperial unit conversion with step-by-step working shown.
Open Volume of a Hexagonal Pyramid Calculator Calculate the volume, base area, lateral surface area, and total surface area of a hexagonal pyramid. Enter base edge and height in metric or imperial units.
Open Volume of a Rectangular Prism Calculator Calculate the volume, surface area, and space diagonal of any rectangular prism. Enter length, width, and height to get instant results with a step-by-step solution.
Open Volume of a Triangular Prism Calculator Calculate the volume of a triangular prism using base and height, three sides, two sides and an angle, or a right triangle. Shows all working steps with unit switching.
Open Volume to Density Calculator Calculate density from volume and mass, or solve for mass or volume. Supports kg/m3, g/cm3, lb/ft3 and more. Instant results with step-by-step working.
Open Wage to Salary Calculator Convert any wage to an equivalent salary across all pay periods: hourly, daily, weekly, biweekly, semi-monthly, monthly, and annual. Add overtime and PTO.
Open Wake-Up Calculator Find the best times to wake up or go to bed based on 90-minute sleep cycles. Choose your mode, enter the time, and get 6 alarm options instantly.
Open Warp Speed Calculator Convert any Star Trek warp factor to multiples of light speed and km/s. Get travel times for famous destinations. Supports TOS and TNG warp scales.
Open Wastewater Treatment Calculator Calculate wastewater pollution load (kg/day), tank volume, effluent concentration, and hydraulic retention time for BOD, COD, or TSS. Metric and imperial units.
Open PC Water Cooling Calculator Calculate coolant flow rate, heat dissipation, temperature rise, and required radiator size for your PC water cooling loop. Metric and imperial units.
Open Wattage to Amperage Calculator Convert watts to amps instantly for DC, AC single-phase, and AC three-phase circuits. Enter watts, voltage, and power factor to find current in amperes.
Open Wave Velocity Calculator Calculate wave speed, frequency, wavelength, or period using v = f x lambda. Choose from 14 preset mediums, switch units, and see a step-by-step solution.
Open Wavelength to Frequency Calculator Convert wavelength to frequency (or frequency to wavelength) for light, sound, or any wave. Choose from 14 preset wave velocities or enter a custom speed.
Open Wavenumber Calculator Convert wavenumber to wavelength, frequency and photon energy instantly. Supports spectroscopic (cm-1) and angular (rad/m) wavenumber with EM-spectrum classification.
Open Wedding Countdown Calculator Find out exactly how many days, weeks, and months until your wedding. Get a full planning timeline, milestone checklist, and a countdown breakdown.
Open Weekly Pay Calculator Convert hourly, daily, monthly, or annual pay to weekly earnings instantly. See all pay periods, overtime impact, and a full pay breakdown in one place.
Open Weeks to Months Calculator Convert weeks to months instantly. See the exact result plus days, years, and a complete worked example. Includes a reference chart and pregnancy milestones.
Open Weird Units Converter Convert length, mass, area, volume, time, speed, energy, and power into funny weird units like bananas, elephants, and lightning bolts. Instant, free, and fun.
Open Well Volume Calculator Calculate well water volume, purge volume, annular grout volume, and total borehole capacity. Supports cylindrical and rectangular wells in US and metric units.
Open False Negative Pregnancy Test Calculator Find your estimated false-negative probability based on days past ovulation and test sensitivity. Understand why testing too early causes missed results.
Open What to Do After a Positive Pregnancy Test Got a positive pregnancy test? Instantly calculate your due date, gestational age, trimester, and a personalised first-steps timeline for a healthy pregnancy.
Open Width of a Rectangle Calculator Find the width of any rectangle from its length and area, perimeter, or diagonal. Includes unit converter, shape visual, step-by-step working, and common formulas.
Open Winning Percentage Calculator Calculate winning percentage from wins, losses, and ties. Get next-game impact, season projections, and wins needed to reach any target - for any sport.
Open Yard to Meter Converter Convert yards to meters instantly. Enter any value in yards and get the exact meter equivalent with the formula, worked example, and a full reference table.
Open Yard to Mile Converter Convert yards to miles or miles to yards instantly. Shows the formula, step-by-step working, a conversion chart, and a quick-reference table for common distances.
Open Yards to Meters Conversion Convert yards to meters instantly with the exact factor 0.9144. Get meters, feet, centimeters, and kilometers from any yard value, with a full conversion table.
Open Years Between Two Dates Calculator Calculate the exact number of years, months, and days between any two dates. Includes decimal years, total days, weeks, and a full calendar breakdown.
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