Physics calculators
Mechanics, waves, electromagnetism and the equations behind them.
413 published calculatorsElectronics And Circuits 51
555 Timer Calculator Calculate 555 timer frequency, period, duty cycle, and pulse width for astable and monostable modes. Instant results with step-by-step formulas for NE555 circuits.
Open Breaker Size Calculator Find the correct circuit breaker size for DC, single-phase, or three-phase loads. Applies the NEC 125% rule for motors, AC units, and general loads. Free online tool.
Open Bridge Rectifier Calculator Calculate DC output voltage, ripple voltage, peak inverse voltage, filter capacitor, efficiency and transformer VA for a full-wave bridge rectifier.
Open Capacitor Calculator Calculate capacitor charge, stored energy, RC time constant, capacitive reactance, and series or parallel equivalent capacitance. Instant results with worked steps.
Open Capacitor Charge Time Calculator: RC Time Constant and Voltage Calculate capacitor charge time for any RC circuit. Get the time constant, voltage at any point, stored energy, and a charge curve chart. Formula shown step by step.
Open Capacitor Energy Calculator Calculate energy stored in a capacitor from capacitance and voltage. Supports pF to F, mV to kV, nJ to kWh, with reverse-solve and step-by-step working.
Open Capacitor Size Calculator Calculate the capacitor size you need for energy storage, power factor correction, or motor start/run applications. Covers reactance and charge outputs.
Open Current Divider Calculator Calculate branch currents in a parallel circuit (2-4 branches). Covers resistive, inductive, and capacitive dividers with step-by-step working and a current breakdown.
Open Dipole Antenna Calculator Calculate dipole antenna length in feet and metres for any frequency. Includes adjustment factor, inverted-vee mode, feedpoint impedance, and HF band reference table.
Open Generator Power Calculator Calculate generator power in kW, kVA, amps, volts, and horsepower for single-phase, three-phase, and DC systems. Includes power factor and motor efficiency.
Open Helical Coil Calculator Calculate helical coil inductance, height, wire length, resistance, magnetic field, stored energy, and resonant frequency. Metric and imperial, with step-by-step math.
Open High Pass Filter Calculator Calculate the cutoff frequency of any passive high-pass filter (RC, RL or LC) in seconds. Get phase shift, gain in dB, roll-off slope and a Bode plot - free online.
Open Ideal Transformer Calculator Calculate turns ratio, primary and secondary voltage, current, reflected impedance, and power for an ideal transformer. Six solve modes with step-by-step math.
Open Inductor Energy Storage Calculator Calculate the energy stored in an inductor instantly. Enter inductance and current to get energy in joules, millijoules, or microjoules. Reverse-solve for L or I.
Open Inductors in Parallel Calculator Calculate the equivalent inductance of inductors wired in parallel. Supports up to 8 inductors, four unit scales, inductive reactance, and step-by-step working.
Open Inductors in Series Calculator Calculate total inductance of inductors in series instantly. Supports H, mH, uH, nH units, up to 8 inductors, reverse-solve, energy stored, and step-by-step math.
Open J-Pole Antenna Calculator Calculate J-pole antenna dimensions: radiator, stub, feedpoint height, stub impedance, and SWR bandwidth. Metric or imperial, any VHF/UHF frequency.
Open LED Resistor Calculator Calculate the current-limiting resistor for LEDs in series or parallel. Get exact ohms, nearest E12/E24 value, power dissipation, and wattage rating instantly.
Open Low Pass Filter Calculator Calculate the cutoff frequency, time constant, phase shift and attenuation of RC, RL, LC and op-amp low-pass filters. Step-by-step solution and Bode chart included.
Open Magnetic Force Between Current-Carrying Wires Calculator Calculate the magnetic force per unit length and total force between two parallel current-carrying wires. Shows attraction vs. repulsion, unit switches, steps, and a chart.
Open Magnetic Force on a Current-Carrying Wire Calculator Calculate the magnetic force on a current-carrying wire using F = BIL sin(theta). Input field, current, length, and angle to get the Lorentz force in Newtons.
Open MOSFET Calculator Calculate MOSFET drain current, transconductance, and power dissipation for N-channel and P-channel devices. Auto-detects cut-off, triode, and saturation regions.
Open MOSFET Threshold Voltage Calculator Calculate MOSFET threshold voltage (Vth) from oxide thickness, substrate doping, flatband voltage, body bias, and temperature, with full derivation and body effect.
Open Noise Figure Calculator Calculate noise figure from SNR, noise factor, or cascaded stages using the Friis formula. Get NF in dB, noise temperature, and a step-by-step breakdown.
Open Ohm's Law Calculator Enter any two of voltage, current, resistance or power and solve the other two with Ohm's Law. Unit prefixes (mV, kV, mA, kohm), full work shown, plus running cost.
Open Parallel Capacitor Calculator: Total Capacitance in Parallel Circuits Calculate total capacitance for up to 10 capacitors in parallel. Supports pF, nF, uF, mF, and F. Shows the formula, step-by-step working, and a per-capacitor breakdown.
Open Parallel Resistor Calculator Find the equivalent resistance of resistors in parallel, switch Ω, kΩ or MΩ units, reverse-solve a missing resistor, and get total current and power from a voltage.
Open Photon Detection Efficiency Calculator (SiPM) Calculate SiPM photon detection efficiency (PDE) from quantum efficiency, fill factor, and triggering probability, or back-calculate PDE from measured responsivity.
Open RC Circuit Calculator Calculate RC circuit time constant, cutoff frequency, capacitive reactance, impedance, phase shift, and voltage at any time t. Series and parallel modes included.
Open Resistor Color Code Calculator (4, 5 & 6 Band) Decode 4, 5 and 6 band resistor color codes to ohms, tolerance and temperature coefficient. Reverse mode finds the bands for any value, with the allowed range.
Open Resistor Noise Calculator Calculate thermal (Johnson-Nyquist) noise voltage, spectral density, noise power and noise level for any resistor. Instant results with worked steps and a noise chart.
Open Resistor Wattage Calculator Calculate the power dissipated by a resistor from any two of voltage, current, and resistance. Get a safe wattage rating with 50 % derating and a power curve chart.
Open Resonant Frequency Calculator (LC and RLC) Find LC resonant frequency with f = 1 / (2π√LC), or reverse solve for L or C. Add resistance for Q factor, bandwidth, reactance and impedance, with full steps.
Open RLC Circuit Calculator Calculate resonant frequency, impedance, Q factor, damping ratio, bandwidth and phase angle for series and parallel RLC circuits instantly.
Open RLC Impedance Calculator Calculate RLC circuit impedance, phase angle, resonant frequency, Q factor, and bandwidth for series and parallel circuits. Instant step-by-step results.
Open RMS Voltage Calculator Convert peak voltage, peak-to-peak voltage, or average voltage to RMS for six waveform types including sine, square, triangle, sawtooth, and rectified waves.
Open Series Resistor Calculator Add resistors in series to get total resistance in Ω, kΩ or MΩ, plus loop current, the voltage drop and power dissipated by each resistor, and a tolerance band.
Open Shockley Diode Calculator Calculate diode current or forward voltage using the Shockley equation. Supports real diodes (n=1-2), temperature input, thermal voltage, and I-V curve output.
Open Solenoid Inductance Calculator Calculate solenoid inductance, stored energy, magnetic field strength, and inductive reactance. Supports air and iron cores, metric and imperial units.
Open Solenoid Magnetic Field Calculator Calculate the magnetic field inside a solenoid from current, turns, and length. Supports core materials, unit switches, reverse-solve, and a field-vs-current chart.
Open Speaker Crossover Calculator Calculate passive crossover capacitor and inductor values for 2-way and 3-way speaker networks. Supports 1st-4th order Butterworth, Linkwitz-Riley, and Bessel filters.
Open Spherical Capacitor Calculator Calculate the capacitance, stored energy, electric field and voltage of a spherical capacitor. Supports dielectric materials and reverse-solve modes.
Open Three-Phase Power Calculator Calculate three-phase apparent, real, and reactive power for balanced Wye or Delta systems. Enter voltage, current, and power factor to get S, P, and Q instantly.
Open Transformer Sizing Calculator Size a single-phase or three-phase transformer from load kW, power factor, and voltages to get required kVA, primary/secondary amps, turns ratio, and a standard rating.
Open Transistor Biasing Calculator Transistor biasing calculator for NPN BJTs: Q-point (Ic, Vce), voltage gain, input impedance, and thermal stability factor across four common biasing topologies.
Open Voltage Divider Calculator Voltage divider calculator: solve for output voltage, input voltage, R1 or R2. Includes load resistance, current, power dissipation, and step-by-step math.
Open Voltage Regulation Calculator Calculate voltage regulation (%) from no-load and full-load voltages, or use the impedance method for transformers. Covers step-up and step-down formulas with worked steps.
Open Wheatstone Bridge Calculator Calculate unknown resistance or output voltage of a Wheatstone bridge. Balanced and unbalanced modes with step-by-step working, Req, current, and sensitivity (mV/V).
Open Wire Gauge Calculator Size copper or aluminum wire for DC, single-phase or three-phase circuits. Get the AWG for a target voltage drop, or check the drop of a chosen gauge.
Open Wire Resistance Calculator Calculate wire resistance, voltage drop, and power loss for any material and gauge. Includes temperature correction, AWG selector, and worked steps.
Open Wire Size Calculator Find the right wire gauge (AWG) for any circuit. Enter current, voltage, length, and material to get the minimum wire size, actual voltage drop, and resistance.
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Thermodynamics And Heat 46
Biot Number Calculator Calculate the Biot number (Bi = hL/k) for any geometry. Reverse-solve for h, L, or k, select a shape, use the material library, and check lumped capacitance validity.
Open Boltzmann Factor Calculator Calculate the Boltzmann factor, population ratio, partition function, and state occupancy probability. Supports eV, J, kJ/mol, kcal/mol, and K/C/F inputs.
Open Boyle's Law Calculator Solve Boyle's law P1V1 = P2V2 for any unknown pressure or volume. Pick from 10 pressure and 7 volume units, see the P-V curve, and find moles of gas.
Open BTU to Tons of Refrigeration Converter Convert BTU/hr to tons of refrigeration, kilowatts, or watts instantly. Enter any unit and get all others with a worked example and HVAC sizing table.
Open Calorimetry Calculator Calculate heat transfer (Q = mcΔT) instantly. Solve for heat, mass, specific heat, or temperature change. Supports J, kJ, cal, g, kg, C, F, K with steps shown.
Open Carnot Efficiency Calculator Calculate Carnot efficiency from hot and cold reservoir temperatures. Supports reverse-solve, actual vs ideal comparison, COP for heat pumps, and power-loss breakdown.
Open Charles's Law Calculator Solve Charles's law V₁/T₁ = V₂/T₂ for any unknown at constant pressure. Switch temperature units (K, °C, °F) and volume units, and find moles with pressure.
Open Coefficient of Performance Calculator Calculate COP for refrigerators and heat pumps using heat values or Carnot temperatures. Shows Carnot limit, second-law efficiency, and both heating and cooling COP.
Open Combined Gas Law Calculator Solve the combined gas law for any pressure, volume, or temperature. Switch units across atm, kPa, bar, mmHg, psi, L, m³, ft³, °C, °F, and K, with full worked steps.
Open Compressibility Factor (Z) Calculator Calculate the compressibility factor Z for real gases using van der Waals, Peng-Robinson, or SRK equations of state. Supports 10 gases, SI and imperial units.
Open Curie's Law Calculator Calculate magnetic susceptibility, magnetization, temperature, or Curie constant with Curie's Law. Includes 8 paramagnetic ion presets and a live chi-vs-T chart.
Open Effectiveness-NTU Calculator Calculate heat exchanger effectiveness, NTU, heat capacity ratio, outlet temperatures and heat transfer rate. Covers 6 flow arrangements with step-by-step math.
Open Efficiency Calculator Solve for efficiency, output, or input. Switch energy or power units, compare to the Carnot limit, and cost the wasted energy. Steps and a gauge included.
Open Electrical Mobility Calculator Calculate electrical mobility, drift velocity, and diffusion constant via the Einstein-Smoluchowski relation. Covers electrons, holes, and ions with worked steps.
Open Enthalpy Calculator Find enthalpy change ΔH four ways: measured heat, Hess formation enthalpies, sensible heat (mcΔT), or phase change (mL). Unit switches, per mole output, full steps.
Open Evaporation Rate Calculator Calculate water evaporation rate by surface area, wind speed, temperature, and humidity. Get results in kg/h, L/h, gal/h, or daily totals with a full step-by-step breakdown.
Open Gay-Lussac's Law Calculator Solve Gay-Lussac's Law (P1/T1 = P2/T2) for any variable. Enter three values, pick pressure and temperature units, and get an instant step-by-step solution.
Open Heat Capacity Calculator Calculate heat energy, specific heat, mass, or temperature change using Q = mcDeltaT. Choose from 50+ material presets, switch units, and see the full worked solution.
Open Heat Transfer Calculator Find the rate of heat transfer by conduction, convection, or radiation, or the heat energy with Q = mcΔT. Unit switches, thermal resistance, and a cost estimate.
Open Heat Transfer Coefficient Calculator Calculate convective heat transfer coefficient (h), overall U-value, heat flux, or total heat transfer Q. Six modes, step-by-step math, SI and imperial units.
Open Ideal Gas Density Calculator Calculate the density of any ideal gas from pressure, temperature, and molar mass. Choose from 15 gas presets or enter a custom mass. Metric and imperial units.
Open Ideal Gas Law Calculator (PV = nRT) Solve PV = nRT for pressure, volume, amount or temperature. Switch units (atm, kPa, bar, psi, L, m³, °C, K, °F), and get molecules, molar volume, mass and density.
Open Isentropic Flow Calculator Calculate isentropic flow relations: Mach number, pressure, temperature, density and area ratios, Mach angle, and Prandtl-Meyer function for compressible gas flow.
Open Joule Heating Calculator Calculate Joule heating with Q = I^2Rt. Find power dissipated, heat energy in joules or kWh, and temperature rise for any conductor or resistor. Free and instant.
Open Latent Heat Calculator Solve Q = m·L for heat, mass, or specific latent heat. Pick a substance preset for fusion, vaporization, or sublimation, switch mass units, and price the energy.
Open LMTD Calculator: Log Mean Temperature Difference Calculate LMTD for parallel flow, counter flow, and shell-and-tube heat exchangers. Includes LMTD correction factor F, R, P parameters, heat duty, and transfer area.
Open Mean Free Path Calculator: Gas Molecules, Vacuum Regimes, and Collisions Calculate mean free path from temperature, pressure, and kinetic diameter. Shows collision frequency, mean speed, and vacuum regime for 14 preset gases.
Open Mixed Air Calculator Calculate the mixed air temperature, relative humidity, humidity ratio, dew point, enthalpy, and mass flow for two blended HVAC air streams. Metric and imperial units.
Open Mixed Air Temperature Calculator HVAC mixed air temperature calculator. Enter stream temperatures and flow rates; get mixed temperature, outdoor-air fraction, and stream percentages in CFM or m3/s.
Open Newton's Law of Cooling Calculator Calculate temperature over time with Newton's Law of Cooling. Solve for final temp, cooling time, or derive k from heat transfer coefficient, area and specific heat.
Open Nusselt Number Calculator Calculate the Nusselt number from h, L and k, or use built-in correlations: Dittus-Boelter, Gnielinski, flat plate and Churchill-Chu natural convection.
Open Particles Velocity Calculator Calculate RMS speed, mean speed, and most probable speed of gas molecules from temperature and molar mass. Includes 14 preset gases with metric and imperial units.
Open Root Mean Square Velocity Calculator Calculate RMS speed of any gas molecule. Choose from 19 gas presets or a custom molar mass. Outputs mean speed, most probable speed, and kinetic energy per mole.
Open Sensible Heat Calculator Calculate sensible heat (Q = mcΔT) or size HVAC airflow loads. 15 material presets, metric/imperial, solve for Q, mass, or ΔT. Step-by-step workings.
Open Specific Gas Constant Calculator Calculate the specific gas constant (Rs) from molar mass or specific heats. Presets for 13 common gases, reverse-solve for molar mass, and a worked-example panel.
Open Specific Heat Calculator Solve Q = m·c·ΔT for heat, mass, specific heat, or temperature change. Pick a substance, switch units, use initial and final temperatures, and price the energy.
Open Thermal Conductivity Calculator Solve heat conduction with Fourier law: heat-transfer rate, flux, R-value, U-value and yearly energy cost. Pick a material or solve for k, thickness, area or ΔT.
Open Thermal Diffusivity Calculator Calculate thermal diffusivity (alpha = k / rho·cp), penetration depth, thermal response time, and Fourier number. Includes 15 material presets and unit switches.
Open Thermal Efficiency Calculator Calculate thermal efficiency from heat input and work output, solve for any variable, find the Carnot limit, and compare second-law efficiency. J, kJ, BTU, cal.
Open Thermal Energy Calculator Calculate thermal energy (Q), mass, specific heat, or temperature change with Q = mcΔT. 30+ material presets, multiple unit options, and step-by-step working shown.
Open Thermal Equilibrium Calculator Calculate the final equilibrium temperature and heat transferred when two objects mix. Supports 18 substances, metric and imperial units, and reverse-solve modes.
Open Thermal Expansion Calculator Find linear, area, or volumetric thermal expansion, thermal stress, and the expansion gap to leave. Pick a material preset or your own coefficient, metric or imperial.
Open Thermal Resistance Calculator Calculate thermal resistance for plates, cylinders, and spheres. Conduction, convection, series and parallel networks with 14 material presets and instant heat flow.
Open Van der Waals Equation Calculator Calculate pressure, volume, temperature, or moles for any real gas using the van der Waals equation. Choose from 12 gas presets or enter custom a and b constants.
Open Water Heating Calculator Calculate time, energy, power, and electricity cost to heat any volume of water. Handles phase changes (ice to steam) with metric or imperial units.
Open Watts to Heat Calculator Convert watts to heat energy (joules, BTU, kWh, kcal) and find temperature rise in any material. Includes 15 substances, unit switches, and reverse power-from-heat mode.
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Fluid Mechanics 46
API Gravity Calculator Convert between API gravity, specific gravity, and density (kg/m3, g/cm3, lb/gal) instantly. Crude oil classification, product presets, and step-by-step math included.
Open Archimedes' Principle Calculator Calculate buoyant force, apparent weight, and float-or-sink status using Archimedes' principle. Choose metric or imperial units and pick from 8 preset fluids.
Open Bernoulli Equation Calculator Calculate pressure, velocity, flow rate, and hydraulic head at two points in a fluid streamline using the Bernoulli equation. Metric and imperial units.
Open Broad-Crested Weir Calculator Calculate discharge, head, weir length, critical depth, and Froude number for a broad-crested weir. Metric and imperial units, five solve modes, step-by-step working.
Open Buoyancy Calculator Find buoyant force with Archimedes’ principle F = ρVg, plus fluid presets, apparent (immersed) weight, float-or-sink check, fraction submerged and metric or imperial units.
Open Coefficient of Discharge Calculator Calculate coefficient of discharge (Cd), actual flow rate, head, or orifice area. Six solve modes, metric/imperial units, edge-type presets, and step-by-step working.
Open Cv Flow Calculator: Valve Flow Coefficient for Liquids and Gases Calculate the Cv valve flow coefficient for liquids and gases. Subcritical and choked gas flow, reverse-solve for flow rate or pressure drop, metric and imperial units.
Open Darcy-Weisbach Calculator Calculate pipe head loss, pressure drop, friction factor, flow velocity, or pipe length with the Darcy-Weisbach equation. Includes Reynolds number and Colebrook-White.
Open Darcy's Law Calculator Calculate flow rate, hydraulic conductivity, gradient, or area using Darcy's Law. Solve any variable, switch units, and see conductivity ranges for nine soil types.
Open Differential Pressure Calculator Calculate differential pressure from two pressures, orifice flow rate, Darcy-Weisbach pipe drop, or filter DP. Includes unit conversion, worked steps, and reference table.
Open Drag Equation Calculator Solve any variable in the drag equation: force, velocity, Cd, area, or density. Six modes, shape presets, unit switches, terminal velocity, and step-by-step workings.
Open Fan Calculator Calculate fan power, airflow (CFM), static pressure and efficiency using the fluid-mechanics fan equations. Includes fan affinity law scaling and BHP output.
Open Flow Rate Calculator Find volumetric flow rate from area or pipe diameter times velocity, or volume over time. Solve for velocity, add mass flow rate, and estimate pumping cost.
Open Friction Factor Calculator (Darcy-Weisbach) Calculate the Darcy friction factor for laminar and turbulent pipe flow using the Colebrook-White equation. Enter pipe diameter, fluid velocity, viscosity and roughness.
Open Friction Loss Calculator Calculate pipe friction loss, pressure drop, and flow velocity using the Hazen-Williams equation. Supports metric and imperial units with 18 pipe materials.
Open Froude Number Calculator Froude number calculator for open channel flow: regime (subcritical, critical, supercritical), critical depth, hydraulic jump sequent depth, and energy dissipation.
Open Hydraulic Conductivity Calculator Calculate hydraulic conductivity (K) via Constant Head, Falling Head, Kozeny-Carman, Hazen, and USBR methods. Step-by-step working in m/s, m/day, cm/s, or ft/day.
Open Hydraulic Gradient Calculator Calculate hydraulic gradient from upstream and downstream head, or solve for head loss, flow path length, or pipe friction using Darcy-Weisbach. Metric and imperial units.
Open Hydraulic Jump Calculator Calculate conjugate depth, head loss, jump length, efficiency and Froude numbers for a hydraulic jump in a rectangular channel. Metric and imperial.
Open Hydraulic Pressure Calculator Calculate hydraulic pressure, force, and area using Pascal's law. Find piston force, system pressure, mechanical advantage, and work done for two-piston systems.
Open Hydraulic Radius Calculator Hydraulic radius calculator for rectangular, trapezoidal, triangular, and pipe sections. Get hydraulic diameter, Manning velocity, and discharge. Metric or imperial.
Open Hydrostatic Pressure Calculator Calculate hydrostatic pressure at any depth. Gauge and absolute pressure, metric and imperial units, 7 fluid presets, reverse-solve for depth or fluid density.
Open Knudsen Number Calculator Calculate the Knudsen number (Kn = lambda/L) with a direct input or kinetic-theory mode. Instant 4-band flow regime: continuum, slip, transition, free-molecular.
Open Lift Coefficient Calculator Calculate lift coefficient (CL) from lift force, wing area, speed, and density. Reverse solve for lift force, angle-of-attack mode, Reynolds number, and L/D ratio.
Open Mach Number Calculator Calculate Mach number from speed and temperature, or solve for velocity or sound speed. Covers subsonic to hypersonic, ISA altitude model, metric and imperial.
Open Magnus Force Calculator Calculate the Magnus force on a spinning ball or cylinder. Enter radius, spin rate, fluid density and velocity to get lift force, spin parameter and lateral deflection.
Open Manometer Calculator Calculate gauge pressure and absolute pressure from a manometer reading. Supports single-column, U-tube single-fluid, U-tube two-fluid, and differential configurations.
Open Oblique Shock Calculator Calculate oblique shock wave angle, downstream Mach number, pressure ratio, density ratio, temperature ratio, and stagnation pressure loss for any supersonic flow.
Open Open Channel Flow Calculator (Manning's Equation) Manning's equation calculator: find flow velocity, discharge, Froude number, and critical depth for rectangular, trapezoidal, triangular, and circular open channels.
Open Orifice Flow Calculator Calculate orifice flow rate, velocity, and area using the Torricelli equation. Metric and imperial units, three solve modes, worked steps, and Cd reference table.
Open Pipe Flow Calculator Calculate pipe flow rate, mean velocity, Reynolds number, Darcy friction factor, and pressure drop in seconds. Metric and imperial units, any pipe material.
Open Pneumatic Cylinder Force Calculator Calculate pneumatic cylinder force for extend and retract strokes. Enter bore, rod diameter, pressure and friction loss to get effective force instantly.
Open Poise to Stokes Converter Convert between poise and stokes (dynamic and kinematic viscosity) using fluid density. Supports cP, Pa*s, cSt, mm2/s and more units. Free, instant, shows all working.
Open Poiseuille's Law Calculator Calculate flow rate, pressure drop, tube radius, length, or viscosity with the Hagen-Poiseuille equation. Reynolds number and flow regime included.
Open Porosity and Permeability Calculator Calculate porosity from void or bulk density, and permeability from Darcy's law or the Kozeny-Carman equation. Shows all steps with standard material ranges.
Open Pounds per Minute Calculator Convert mass flow rate to and from pounds per minute. Enter mass and time, or volume and density, to get lb/min plus 8 other unit conversions instantly.
Open Prandtl Number Calculator: Pr from Viscosity, Heat Capacity and Conductivity Calculate the Prandtl number from dynamic viscosity, specific heat and thermal conductivity. Covers air, water, oils, mercury and custom fluids with worked steps.
Open Prandtl-Meyer Expansion Calculator Calculate Prandtl-Meyer expansion fan properties: downstream Mach, pressure ratio, temperature ratio, density ratio, and Mach angles. Three solve modes, any gas.
Open Refrigerant Capillary Tube Calculator Calculate capillary tube size or refrigerant mass flow rate. Tube resizer (ASHRAE) plus flow analysis with Reynolds number, friction factor, and exit quality.
Open Reynolds Number Calculator Compute the Reynolds number from preset fluids or your own values. Use metric or imperial, velocity or pipe flow rate, dynamic or kinematic viscosity, classify flow.
Open Stokes' Law Calculator Calculate terminal settling velocity, drag force, Reynolds number, and settling time using Stokes' law. Reverse-solve for particle size, density, or viscosity.
Open Water Density Calculator Calculate water density by temperature, salinity, and pressure. Get results in kg/m3, g/cm3, and lb/ft3 with full step-by-step working and a reference table.
Open Water Viscosity Calculator Calculate the dynamic viscosity, kinematic viscosity, and density of liquid water at any temperature, in Celsius, Fahrenheit, or Kelvin, with a chart.
Open Wind Correction Angle Calculator Calculate wind correction angle (WCA), true heading, ground speed, headwind, crosswind, and ETA for any flight leg. Supports knots, mph, and km/h with step-by-step math.
Open Wind Load Calculator Calculate wind pressure and total wind force on buildings in metric or imperial units. Uses the ASCE 7 formula with exposure category, gust factor, and directionality.
Open Y+ Calculator Calculate the y+ wall distance or first cell height for CFD turbulence models. Covers k-epsilon, SST k-omega, Spalart-Allmaras and LES. Metric and imperial units.
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Electromagnetism 41
AC Wattage Calculator Calculate AC wattage from amps and volts (single or three-phase) or from BTU and EER rating. Includes daily, monthly, and yearly electricity cost estimates.
Open Acceleration in the Electric Field Calculator Calculate the acceleration, force, final velocity, and kinetic energy of a charged particle in a uniform electric field. Includes electron, proton, and alpha-particle presets.
Open Capacitance Calculator Find capacitance from charge and voltage (C = Q/V) or from parallel plate geometry (κ·ε0·A/d) with a dielectric table. Get stored charge, energy, and field strength.
Open Conductivity to Resistivity Calculator Convert electrical conductivity to resistivity or reverse. Choose a preset material or enter a custom value with unit switches, worked steps, and a materials reference table.
Open Coulomb's Law Calculator Calculate the electrostatic force between two charges using Coulomb's Law. Solve for force, charge, or distance with metric unit switching and step-by-step math.
Open Cutoff Frequency Calculator: RC, RL, and LC Filters Find the -3 dB cutoff frequency for RC, RL, or LC filters. Reverse-solve for R, C, or L. Shows time constant, angular frequency, Bode plot, and step-by-step math.
Open Cyclotron Frequency Calculator Calculate cyclotron frequency, angular frequency, and orbital period for protons, electrons, and alpha particles. Particle presets, unit switches, and worked steps.
Open Delta to Wye Conversion Calculator Convert resistor networks between delta and wye (star) configurations. Enter three resistance values, get the equivalent network instantly, with step-by-step working.
Open Dipole Moment Calculator Calculate the electric dipole moment from charge and separation, or reverse-solve for charge or distance. Get results in Debye and C*m with a worked example.
Open Drift Velocity Calculator Calculate drift velocity using three methods: current-density, mobility times field, or Drude model. Includes worked steps, reference table, and charts.
Open Electric Field Calculator Find electric field strength three ways: from a point charge (E = kq/r²), parallel plates (E = V/d), or force on a test charge (E = F/q), with force output.
Open Electric Motor Torque Calculator Calculate electric motor torque from power and speed, or find synchronous speed and slip for AC motors, or solve DC motor torque from voltage, current and efficiency.
Open Electric Potential Calculator Calculate electric potential V = kq/r for a point charge. Reverse-solve for charge or distance, compute potential difference, and apply superposition for two charges.
Open Electrical Power Calculator Calculate electrical power (watts), voltage, current, and resistance instantly. Enter any two values and solve all four using Ohm's Law and Watt's Law.
Open Energy Density of Fields Calculator Calculate energy density stored in electric and magnetic fields. Supports vacuum and custom media, total energy from volume, and reverse-solve for field strength.
Open Excess Electrons Calculator Convert electric charge (coulombs) to the number of excess electrons, or find the charge from an electron count. Shows the full worked calculation.
Open Faraday's Law Calculator Calculate induced EMF, magnetic flux change, number of turns, time interval, or coil area using Faraday's law. Six solve modes with step-by-step working.
Open Free Space Path Loss Calculator Calculate free space path loss in dB from frequency, distance, antenna gains and feeder losses. Instant results with a worked example, chart, and link budget.
Open Fresnel Zone Calculator Calculate the first Fresnel zone radius, obstruction clearance, nth zone radius, and earth-bulge correction for any wireless link. Metric and imperial, instant results.
Open Gauss's Law Calculator Calculate electric flux, field strength, and enclosed charge with Gauss's Law. Supports spherical, cylindrical, planar, and general surfaces with step-by-step math.
Open Hall Coefficient Calculator Calculate the Hall coefficient, carrier concentration, mobility, Hall angle and resistivity from Hall voltage, sample thickness, current and magnetic field.
Open HP to Amps Calculator Convert horsepower to amps instantly for DC, single-phase, and three-phase AC motors. Enter HP, voltage, efficiency, and power factor to get full-load current.
Open Inductive Reactance Calculator Calculate inductive reactance (XL), frequency, or inductance instantly. Supports Hz to GHz, H to nH unit switching, admittance output, and a worked example.
Open Insertion Loss Calculator Calculate insertion loss in dB from power or voltage ratios, cascade multiple segments, or budget a fiber optic link with connectors, splices and attenuation.
Open Internal Resistance Calculator Calculate internal resistance, EMF, terminal voltage, current, power loss, and efficiency for any battery or voltage source. Solve for any unknown in seconds.
Open kVA Calculator Calculate kVA from amps and voltage, or from kW and power factor, for single-phase and three-phase systems. Get kW, kVAR, and amps instantly.
Open Lorentz Force Calculator Calculate the Lorentz force on a moving charged particle. Solve for force, charge, velocity, field, or angle, with particle presets and worked steps.
Open Magnetic Declination Calculator Calculate magnetic declination by latitude, longitude, and date. Get the angle between true north and magnetic north, the annual change rate, and corrected bearings.
Open Magnetic Dipole Moment Calculator Calculate the magnetic dipole moment of a current loop, solenoid, or permanent magnet. Get torque and potential energy in an external field, with step-by-step working.
Open Magnetic Field of a Straight Current-Carrying Wire Calculator Calculate the magnetic field produced by a long, straight current-carrying wire using the Biot-Savart law. Solve for B, current, or distance with unit switching.
Open Magnetic Permeability Calculator Calculate permeability, relative permeability, susceptibility, flux density, field strength, and permeance. Six solve modes with a material reference table.
Open Power Dissipation Calculator Find electrical power dissipated as heat from any two of voltage, current and resistance, or across a series or parallel resistor network, with cost estimate.
Open Power Factor Calculator Calculate power factor, real power, reactive power, apparent power, phase angle, impedance and correction capacitor size for single-phase and three-phase AC circuits.
Open Skin Depth Calculator Calculate electromagnetic skin depth for copper, aluminum, silver, iron and custom conductors. Full formula, worked example, frequency chart and material table.
Open Volt to Electron Volt Calculator Convert volts to electron volts instantly. Enter voltage and charge in elementary charges or coulombs. Includes the V to eV formula and reverse eV to V conversion.
Open Voltage Drop Calculator Find voltage drop, percent drop and voltage at the load for DC, single or three phase runs. Pick a wire size or enter resistance, with power factor and energy cost.
Open VSWR Calculator - Voltage Standing Wave Ratio Calculate VSWR, reflection coefficient, return loss, mismatch loss, and reflected power from any RF input. Switch between VSWR, return loss, and impedance modes.
Open Watt Calculator Solve for power, voltage, current, or resistance. Enter any two quantities to get the others with Ohm and Watt laws, for DC and AC with power factor.
Open Watt-Hour Calculator Calculate watt-hours from watts and time or from volts and amp-hours. Get kWh, amp-hours, battery runtime, and daily electricity cost in one tool.
Open Watts to Amps Calculator Convert watts to amps for DC, single-phase and three-phase AC. Set voltage, power factor and line type, see the work, milliamps, and an optional running-cost estimate.
Open Watts to Lux Calculator Convert watts to lux instantly using luminous efficacy and area. Supports 11 light source presets, metric and imperial area, and reverse lux-to-watts mode.
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Materials And Continuum Mechanics 39
Angle of Repose Calculator Calculate the angle of repose from heap geometry or friction coefficient. Includes flowability classification, material reference table, and worked steps.
Open Angle of Twist Calculator Calculate the angle of twist, shear stress, polar moment, and torque capacity for solid or hollow shafts. Metric and imperial units, material presets, worked steps.
Open Bend Allowance Calculator Calculate bend allowance, bend deduction, and flat blank length for any sheet metal bend. Enter thickness, inside radius, bend angle, and K-factor for instant results.
Open Brinell Hardness Number Calculator (HBW) Calculate Brinell hardness (HBW) from applied load, ball diameter and indentation diameter. Metric and imperial units, step-by-step solution, ISO 6506-1 formula.
Open Buckling Calculator Calculate the critical buckling load for a column using the Euler or Johnson formula. Enter length, moment of inertia, material, and end conditions. Instant results.
Open Bulk Modulus Calculator Calculate bulk modulus from pressure and volume change in Pa, kPa, MPa, GPa or psi. Forward and reverse solve, show-your-work steps, and a material reference table.
Open Copper Wire Weight Calculator Calculate copper wire weight by AWG gauge or diameter. Supports metric and imperial units, insulation types, bundle weight, cost estimate, and reverse length solve.
Open Density Calculator Find density, mass, or volume with ρ = m/V. Switch metric and imperial units, build volume from box dimensions, get specific gravity, and compare to common materials.
Open Elastic Constants Calculator Convert any two elastic constants to all six: Young's modulus, shear modulus, bulk modulus, Poisson's ratio, Lame's constant, and P-wave modulus. All 15 pairs.
Open Elongation Calculator Calculate percent elongation, true strain, and axial deformation for any material. Includes material presets, elongation-at-break comparison, and a stress-strain chart.
Open Factor of Safety Calculator Calculate the factor of safety from stress or load values. Supports material presets, yield vs. ultimate strength, unit switching, and FoS reference ranges by application.
Open Gold Weight Calculator Calculate the weight of a gold object by shape and karat - sheet, wire, tube, bead or ring. Get mass in grams and troy ounces plus an optional value estimate.
Open Hoop Stress Calculator Calculate hoop (circumferential) stress in thin-walled cylinders and spheres. Includes longitudinal stress, safety factor, and diameter change. Metric and imperial.
Open Impact Test Calculator - Charpy and Izod Calculate Charpy and Izod impact energy absorbed, impact strength, capacity utilization, and impact velocity. Height mode, angle mode, metric and imperial units.
Open Intrinsic Carrier Concentration Calculator Calculate intrinsic carrier concentration for silicon, germanium, and GaAs at any temperature. Uses the Varshni band-gap model and Misiakos empirical formula.
Open Mohr's Circle Calculator Calculate principal stresses, maximum shear stress, von Mises stress and rotation angle from a 2D plane stress state. Shows full step-by-step Mohr's circle math.
Open Natural Frequency Calculator Calculate natural frequency for spring-mass, cantilever, simply-supported, and fixed-fixed beam systems. Get results in Hz, rad/s, period, and RPM instantly.
Open Number Density Calculator Calculate number density from mass density and molar mass, ideal gas pressure and temperature, or free-electron carrier concentration. Step-by-step math included.
Open Poisson's Ratio Calculator Calculate Poisson's ratio from lateral and axial strain, Young's and shear moduli, or bulk modulus. Get derived moduli and a worked step-by-step breakdown.
Open Principal Stress Calculator Calculate principal stresses (sigma1, sigma2), max shear stress, Von Mises stress and principal angle for any plane stress state. Step-by-step working shown.
Open Rockwell Hardness Conversion Calculator Convert Rockwell hardness (HRC, HRB) to Vickers HV, Brinell HBW, Knoop HK, and approximate tensile strength for steel. Based on ASTM E140 reference data.
Open Section Modulus Calculator Calculate elastic and plastic section modulus, second moment of area, and maximum bending stress for rectangles, I-beams, pipes, T-sections and more.
Open Shear Modulus Calculator Calculate shear modulus G from shear stress and strain, force and geometry, or Young's modulus and Poisson's ratio. Metric and imperial units with step-by-step working.
Open Shear Strain Calculator Calculate shear strain by displacement, shear stress/modulus, or torsion. Three modes, instant results, step-by-step working shown for each method.
Open Shear Stress Calculator Calculate shear stress using direct (F/A), torsional (Tr/J), or transverse beam (VQ/It) formulas. Metric and imperial units, factor of safety, step-by-step solution.
Open Shear Wave Velocity Calculator Calculate shear wave velocity from shear modulus and density, reverse-solve for G or rho, find wavelength or frequency, and classify seismic site class (NEHRP Vs30).
Open Slenderness Ratio Calculator Calculate slenderness ratio (KL/r) for structural columns. Covers end conditions, cross-section shapes, Euler critical load, critical stress, and column classification.
Open Specific Gravity Calculator Convert density to specific gravity or solve it in reverse. Pick a substance preset, set water temperature, and see if it floats, sinks, plus density and API gravity.
Open Stiffness Matrix Calculator Calculate the local and global stiffness matrix for 2D truss, beam, and frame elements. Euler-Bernoulli formulation, instant results, worked steps, and DOF reference.
Open Stress Calculator Calculate mechanical stress (σ = F/A), strain (ε = ΔL/L), and Young's modulus with unit switches, material presets, and a full worked-step panel.
Open Stress Concentration Factor Calculator Calculate Kt, notch sensitivity q, and fatigue notch factor Kf for plates with holes and shoulder fillets. Free online tool with worked steps and charts.
Open Thermal Stress Calculator: Stress, Strain, Force and Expansion Calculate thermal stress, strain, axial force, and free expansion for 11 preset materials or custom inputs. Metric and imperial with step-by-step working.
Open Torsional Constant Calculator Calculate the St. Venant torsional constant J for solid circles, rectangles, hollow pipes, ellipses, and I-sections. Includes angle of twist and shear stress.
Open Torsional Stiffness Calculator Calculate torsional stiffness, angle of twist, shear stress, and power for solid or hollow circular shafts. Metric and imperial units, step-by-step working.
Open True Strain Calculator: Logarithmic Strain, True Stress and Multi-Pass Deformation Calculate true (logarithmic) strain from length, engineering strain, or cross-sectional area. Includes true stress conversion and multi-pass deformation totals.
Open Vickers Hardness Number Calculator: HV Formula and Conversions Calculate Vickers Hardness Number (HV) from load and diagonal, reverse-solve for force or diagonal, and convert HV to Brinell, Rockwell C, and tensile strength.
Open Volume to Mass Calculator Convert volume to mass (or mass to volume) for 50+ materials. Enter volume and density or pick a preset material. Supports metric and imperial units. Instant results.
Open Von Mises Stress Calculator Calculate von Mises stress from plane stress, a 3D stress tensor, or principal stresses. Get the utilization ratio and factor of safety against yield.
Open Young's Modulus Calculator Calculate Young's modulus from stress and strain, or derive stress or strain from a known modulus, with force, area, and length-change inputs and unit switches.
Open
Optics And Light 29
Angular Resolution Calculator Diffraction-limited angular resolution calculator: Rayleigh, Dawes, and Sparrow criteria. Outputs in arcseconds, arcminutes, degrees, and linear resolution at distance.
Open Aperture Area Calculator Calculate lens aperture area from diameter or focal length and f-number. Get instant results in mm, cm, or inches with a step-by-step breakdown and f-stop reference table.
Open Binoculars Range Calculator Calculate the distance to an object using binocular reticle readings, or solve for object size, angular size, exit pupil, and field of view. Metric and imperial.
Open Blackbody Radiation Calculator Calculate peak wavelength (Wien's law), total radiated power (Stefan-Boltzmann), and Planck spectral radiance for any temperature. Includes a spectral chart and worked steps.
Open Bragg's Law Calculator Calculate Bragg diffraction angle, interplanar d-spacing, X-ray wavelength, or diffraction order with unit switching (pm, nm, Angstrom) and a worked step panel.
Open Brewster's Angle Calculator Calculate Brewster's angle for any two media. Instantly find the polarizing angle, Fresnel reflectances (Rs and Rp), refraction angle, and degree of polarization.
Open Contact Lens Vertex Calculator Convert your glasses prescription to contact lens powers instantly. Handles sphere, cylinder, toric lenses, and adjustable vertex distance with step-by-step working.
Open Diffraction Grating Calculator Calculate diffraction angle, wavelength, line density, max order, angular dispersion, and resolving power for any grating. Steps and multi-order chart included.
Open Diopter Calculator Convert between diopters and focal length, solve the thin-lens equation for image distance, compute magnification, combined lens power, and vergence in one free tool.
Open Distance to Horizon Calculator Calculate how far you can see to the horizon from any height. Supports metric and imperial, multiple planets, atmospheric refraction, and reverse solve.
Open Earth Curvature Calculator Calculate the Earth's curvature drop, hidden height of distant objects, and horizon distance. Includes atmospheric refraction, metric and imperial units.
Open Index of Refraction Calculator Solve Snell's law for refraction angle, incidence angle, or refractive index. Includes critical angle, phase velocity, 18 material presets, and step-by-step math.
Open Laser Beam Divergence Calculator Calculate laser beam divergence half-angle, Rayleigh range, beam radius, and Beam Parameter Product. Supports Gaussian beam physics and the two-diameter method.
Open Laser Beam Expander Calculator Calculate output beam diameter, divergence, magnification and lens separation for Galilean and Keplerian beam expanders. Covers both design modes with worked steps.
Open Laser Beam Spot Size Calculator Calculate focused laser beam spot size, depth of field, Rayleigh range, and beam radius. Supports M2 beam quality, multiple unit systems, and step-by-step math.
Open Laser Brightness Calculator Calculate laser brightness from power, beam waist and divergence. Find required power, max divergence, M2 beam quality, fiber coupling efficiency and etendue.
Open Laser Linewidth and Bandwidth Calculator Convert laser bandwidth between wavelength (nm) and frequency (GHz), calculate coherence time, coherence length, and quality factor. Free physics calculator.
Open Lens Maker Equation Calculator Calculate focal length and optical power from lens radii and refractive index. Supports thin and thick lens modes with material presets and a sign-convention guide.
Open Lumen Calculator - Lumen to Lux to Candela Convert lumens to lux to candela instantly. Six photometric modes: choose your known values and get luminous flux, intensity, and illuminance with step-by-step math.
Open Lux to Foot Candles Converter Convert lux to foot candles (fc) or foot candles to lux instantly. Exact formula, worked example, IES-recommended levels by room type, and a full reference table.
Open Malus's Law Calculator Calculate transmitted light intensity using Malus's law. Enter initial intensity and polarizer angle to find I = I0 cos²(theta). Reverse-solve for angle or source intensity.
Open Mirror Equation Calculator Solve the mirror and lens equation 1/f = 1/do + 1/di for any unknown. Get image distance, magnification, radius of curvature, image height, and a worked solution.
Open Radar Horizon Calculator Calculate radar horizon distance and maximum target detection range with atmospheric refraction (4/3 Earth model). Supports metric, imperial, and nautical units.
Open Snell's Law Calculator: Refraction Angle, Refractive Index and Critical Angle Solve Snell's law for refraction angle, incidence angle, or refractive index. Computes critical angle, TIR check, speed ratio, and shows full step-by-step working.
Open Speed of Light Calculator Calculate light travel time, distance covered, or speed in any medium. Supports vacuum, water, glass, fibre and diamond with full unit conversion.
Open Telescope Field of View Calculator: Magnification, Exit Pupil & Image Scale Calculate your telescope's true field of view, magnification, exit pupil, image scale, and limiting magnitude from focal length, aperture, and eyepiece data.
Open Telescope Magnification Calculator: Eyepiece, Exit Pupil, Field of View Calculate telescope magnification, exit pupil, true field of view, resolving power, and limiting magnitude. Works with any eyepiece, Barlow, or focal reducer.
Open Thin Lens Equation Calculator Solve the thin lens equation (1/do + 1/di = 1/f) for focal length, object or image distance, and magnification. Shows your work, image type, and orientation.
Open Thin-Film Optical Coating Calculator Calculate thin-film optical coating reflectance, OPD, s and p polarization, interference type, and minimum anti-reflective coating thickness using Fresnel equations.
Open
Kinematics 26
Arrow Speed Calculator Convert your bow's IBO rating to real-world arrow speed. Get fps, kinetic energy in ft-lb, and momentum with hunting suitability ratings in one free calculator.
Open Ballistic Coefficient Calculator Calculate ballistic coefficient (BC) using mass, diameter, and form factor or drag coefficient. Supports G1 and G7 models with show-your-work steps.
Open Car Jump Distance Calculator Calculate how far a car jumps from a ramp using projectile motion. Get horizontal range, max height, flight time, landing speed, and landing angle instantly.
Open Conservation of Momentum Calculator Find final velocities for elastic, inelastic, and explosion collisions using conservation of momentum. Step-by-step math, kinetic energy change, and comparison chart.
Open Displacement Calculator Find displacement three ways: constant velocity (d = vt), average velocity (s = ½(u+v)t), or acceleration (s = ut + ½at²). Solves final velocity, metric or imperial.
Open Free Fall Calculator Free fall calculator: solve from time, drop height or impact speed, add initial velocity, switch metric or imperial, and pick gravity for Earth, Moon, Mars or Jupiter.
Open Free Fall with Air Resistance Calculator Calculate terminal velocity, fall time, and drag force for any falling object. Enter mass, altitude, drag coefficient, and area for instant results with step-by-step math.
Open Friction Calculator Solve F = μN for friction force, coefficient, or normal force. Handles inclines, applied force, net force, acceleration, slip angle, and energy lost to friction.
Open Ground Speed Calculator Calculate aircraft ground speed, wind correction angle, heading, and headwind/crosswind components from true airspeed, wind speed, and wind direction.
Open Horizontal Projectile Motion Calculator Calculate horizontal projectile motion instantly: range, time of flight, impact speed, and impact angle from height and launch velocity, with a live trajectory chart.
Open Impulse and Momentum Calculator Calculate impulse, momentum, force, time, mass, or velocity using the impulse-momentum theorem. Nine solve modes, metric and imperial units, step-by-step math.
Open Inclined Plane Calculator Solve a ramp: parallel, normal and friction forces, acceleration, slide time and final speed, the force to push a load up, and the inclined plane mechanical advantage.
Open Magnitude of Acceleration Calculator Find the magnitude of acceleration using components, velocity change, force/mass, or centripetal motion. Five modes with step-by-step working and unit options.
Open Maximum Height Calculator - Projectile Motion Calculate the maximum height of a projectile from launch speed, angle and initial height. Shows time to peak, range, flight time and worked steps. Metric and imperial.
Open Momentum Calculator Calculate momentum p = mv, or reverse solve for mass or velocity. Switch mass and speed units, add a 2D component for magnitude and direction, and see kinetic energy too.
Open Polar Moment of Inertia Calculator Calculate the polar moment of inertia (J) and polar section modulus (Zp) for solid circles, hollow shafts, squares, and rectangles. Metric and imperial units.
Open Projectile Motion Calculator Solve projectile motion for range, max height, flight time, impact speed and angle, and the full trajectory. Metric or imperial, planetary gravity, plus show-your-work steps.
Open Projectile Range Calculator Calculate horizontal range, max height, time of flight, and velocity components for any projectile. Metric and imperial, 4 solve modes, trajectory chart.
Open Quarter Mile Calculator Predict quarter and eighth mile ET, trap speed and 60-foot time from weight and power, or reverse-solve horsepower from a measured run. Fox, Hale and Huntington.
Open Resultant Velocity Calculator Add up to four velocity vectors by magnitude and angle or by Vx/Vy components. Get resultant speed, direction, and components instantly in m/s, km/h, or mph.
Open Rolling Resistance Calculator Calculate rolling resistance force, power loss, grade resistance, and total tractive force for any vehicle. Includes 13 surface/tire presets, metric and imperial units.
Open Sled Ride Calculator Calculate your sledding speed, time down the hill and stopping distance. Choose sled type, hill angle and length. Metric and imperial units, step-by-step physics.
Open SUVAT Calculator Enter any 3 SUVAT values (displacement, velocity, acceleration, time) and instantly solve the remaining 2 with step-by-step working. Supports metric and imperial units.
Open Terminal Velocity Calculator Find terminal velocity from mass, area, drag coefficient and fluid density. Pick a shape or fluid preset, get speed in m/s, km/h and mph, plus time and drag force.
Open Trajectory Calculator Calculate projectile trajectory: horizontal range, maximum height, flight time, and velocity components for any launch speed, angle, and initial height.
Open Velocity Calculator Find velocity three ways: displacement over time, final velocity from acceleration (v = u + at), or the average over multiple legs. Results in m/s, km/h, mph and ft/s.
Open
Machines And Mechanisms 24
Belt Length Calculator Calculate belt length for a two-pulley system using the exact or engineering-approximation formula. Get wrap angles, straight-run length and a step-by-step solution.
Open BMEP Calculator - Brake Mean Effective Pressure Calculate BMEP from torque and displacement for 2-stroke and 4-stroke engines. Includes reverse solve, power output, unit conversions, and engine benchmark ranges.
Open Carburetor CFM Calculator Find the right carburetor CFM for any engine. Enter displacement, RPM, and volumetric efficiency to get the required airflow plus the nearest standard carb size.
Open Crawl Ratio Calculator Calculate your 4WD crawl ratio from transmission, transfer case, and axle ratios. Get vehicle speed, distance per revolution, and a performance rating.
Open Engine Displacement Calculator Calculate engine displacement from bore, stroke, and cylinder count in cc, litres, or cubic inches. Also reverse-solves bore from a known displacement target.
Open Exhaust Diameter Calculator Find the ideal exhaust pipe diameter for your engine by horsepower or displacement and RPM. Covers single and dual exhaust, turbo engines, and exhaust velocity.
Open Fulcrum Calculator Solve any lever problem: find effort force, load force, fulcrum position or mechanical advantage for Class 1, 2 and 3 levers in metric or imperial units.
Open Gear Ratio Calculator Find the gear ratio from tooth counts, then get output rpm, output torque with efficiency losses, a second compound stage, and a reverse-solve mode to hit a target ratio.
Open Lever Calculator Calculate mechanical advantage, effort force, load force, and arm lengths for Class 1, 2, and 3 levers. Metric and imperial units, instant results.
Open Linear Actuator Force Calculator Calculate linear actuator force for inclined, horizontal, or vertical lift. Get gravity, friction, and inertia components plus a design force with safety factor.
Open Mechanical Advantage Calculator Find mechanical advantage for a lever, pulley, screw, wedge, ramp, wheel and axle, or forces. Add efficiency for actual MA and solve the effort needed to lift a load.
Open NPSH Calculator - Net Positive Suction Head Calculate NPSHa for any pump system. Enter pipe size, flow rate, fluid temperature and static head to get NPSHa vs NPSHr with full cavitation margin check.
Open Piston Force Calculator Calculate hydraulic or pneumatic piston extend and retract force, bore area, and effective area. Reverse-solve for required pressure or bore diameter.
Open Piston Speed Calculator Calculate mean piston speed and peak piston speed from engine stroke and RPM. Metric and imperial, with performance bands and engine benchmark table.
Open Prop Pitch Calculator Calculate boat speed from propeller pitch and RPM, or reverse-solve for pitch, RPM, gear ratio, or prop slip. Works in mph, knots, and kph with live step-by-step math.
Open Pulley Calculator Calculate belt drive RPM, belt speed, belt length, torque, and power or find the mechanical advantage of a pulley block. Metric and imperial, with step-by-step working.
Open Pump Horsepower Calculator Calculate water horsepower (WHP), brake horsepower (BHP), and hydraulic pump HP from flow rate, head or pressure, fluid density, and efficiency. Metric and imperial.
Open Shaft Size Calculator Find the minimum shaft diameter for torque, power, combined bending, or torsional rigidity. Solid or hollow, metric or imperial, with material presets and ASME factors.
Open Speeds and Feeds Calculator Calculate CNC milling RPM, feed rate, chipload and MRR from tool diameter, surface speed, flutes and material. Metric and imperial, with recommended starting values.
Open Spring Calculator (Hooke's Law) Calculate spring force, spring constant, displacement, or elastic potential energy using Hooke's Law. Metric and imperial units, worked steps, and a chart included.
Open Spring Rate Calculator Calculate coil spring rate from wire diameter, coil diameter and active coils. Includes wheel rate, motion ratio, spring force and natural frequency.
Open Torsion Spring Calculator Calculate torsion spring torque, spring rate, wire stress, and spring index from wire diameter, coil diameter, active coils, and deflection angle. Metric and imperial.
Open Twist Rate Calculator Barrel twist rate calculator using Miller Twist Rule or Greenhill formula. Get the gyroscopic stability factor with altitude, temperature, and velocity corrections.
Open Wing Loading Calculator Calculate aircraft wing loading, wing cube loading, stall speed, and turn radius. Metric and imperial units, preset aircraft data, and RC model handling categories.
Open
Rotational And Periodic Motion 22
Angular Acceleration Calculator Calculate angular acceleration from velocity change, torque/inertia, or tangential acceleration. Step-by-step solution, chart, and rad/s2, RPM/s, deg/s2 conversions.
Open Angular Displacement Calculator Calculate angular displacement in radians, degrees, or rotations using arc length, angular velocity, or kinematics. Three formula modes with step-by-step working.
Open Angular Frequency Calculator Calculate angular frequency (omega) from frequency, period, RPM, angular displacement, or spring-mass constants. Instant results in rad/s with step-by-step math.
Open Angular Momentum Calculator Find angular momentum from moment of inertia and spin (L = Iω) or a point mass (L = mvr), reverse solve any variable, switch RPM and imperial units, get spin energy.
Open Angular Velocity Calculator Find angular velocity from rpm, frequency, an angle over time, or linear speed and radius. Get ω in rad/s, rpm, deg/s, the period, plus optional kinetic energy and momentum.
Open Centrifugal Force Calculator Calculate centrifugal force, mass, radius, velocity, or angular velocity. Supports RPM, rad/s, metric and imperial units, plus G-force output and step-by-step math.
Open Centrifuge Calculator Convert between RCF (g-force), RPM, and rotor radius for any lab centrifuge. Three-way solve, rotor presets, application reference table, and step-by-step math.
Open Centripetal Force Calculator Solve centripetal force, mass, speed or radius with F = mv²/r or F = mω²r. Switch metric and imperial units, enter speed or angular velocity, and see g-force.
Open Circular Motion Calculator Calculate period, frequency, angular velocity, linear speed, centripetal acceleration, centripetal force and arc length for circular motion. Metric and imperial units.
Open Coriolis Effect Calculator Calculate Coriolis force, acceleration, and deflection distance for any object moving on Earth. Enter mass, velocity, latitude, and time to see the full result.
Open Damping Ratio Calculator Calculate the damping ratio from mass, spring constant, and damping coefficient. Identifies underdamped, critical, or overdamped systems with worked steps.
Open Flywheel Energy Storage Calculator Calculate flywheel stored energy, moment of inertia, angular velocity, surface speed and specific energy for five standard geometries in metric or imperial units.
Open Frequency Calculator Find frequency in hertz from a period (f = 1/T), wave speed and wavelength (f = v/λ), or RPM. Get period, angular frequency, and kHz/MHz/GHz units instantly.
Open Harmonic Wave Equation Calculator Solve y(x,t) = A sin(kx - wt + phi) instantly. Get displacement, wave speed, angular frequency, wavenumber, and period with full step-by-step working.
Open Kinetic Energy of a Pendulum Calculator Calculate the kinetic energy of a pendulum at any swing angle using energy conservation. Get KE, velocity, height drop, potential energy, and period instantly.
Open Physical Pendulum Calculator Calculate the period, frequency, equivalent length, and maximum energy of a physical pendulum, with metric and imperial units and a step-by-step solution.
Open Rotational Kinetic Energy Calculator Calculate rotational kinetic energy from moment of inertia and angular velocity. Supports RPM, rad/s, 8 object shapes, unit switching, and step-by-step working.
Open Rotational Stiffness Calculator Calculate rotational stiffness from torque and angle, shaft stiffness (GJ/L), beam stiffness (EI/L), natural frequency, and torsional energy. Six solve modes.
Open Simple Harmonic Motion Calculator Calculate simple harmonic motion: period, frequency, angular frequency, displacement, velocity, acceleration, and energy. Supports spring-mass and pendulum systems.
Open Simple Pendulum Calculator Calculate pendulum period, frequency, length, or gravity instantly. Metric and imperial units, planet gravity presets, step-by-step working shown.
Open Torque Calculator Compute torque from force, lever arm and angle with τ = F·r·sin(θ), or reverse-solve for any missing variable. Metric and imperial units, in N·m, lbf·ft and kgf·m.
Open Wavelength Calculator Find wavelength from speed and frequency with λ = v / f, or reverse-solve frequency from wavelength. Get photon energy, wavenumber, and the spectrum band.
Open
Acoustic Waves 16
Acoustic Impedance Calculator Calculate acoustic impedance Z = rho x c, intensity reflection and transmission coefficients for any two materials. Choose from 18 presets or enter custom values.
Open Alfven Velocity Calculator Calculate Alfven wave speed from magnetic field strength and plasma density. Includes plasma beta, Alfven Mach number, ion inertial length, and worked steps.
Open Beat Frequency Calculator Find the beat frequency, beat period, average pitch and amplitude swing of two close tones, reverse solve a missing frequency, or analyse detuning in cents for tuning.
Open Critical Damping Calculator Calculate the critical damping coefficient, damping ratio, natural frequency, damped frequency, and settling time for any spring-mass-damper system. Free online tool.
Open dB Calculator: Decibels, Sound Pressure and Intensity Calculate decibels from sound pressure (SPL), intensity (SIL), or power/voltage ratios. Convert dB back to linear. Includes worked steps and common-sounds reference table.
Open dB Gain Calculator Calculate decibel gain from power or voltage ratios instantly. Power gain (10 log), voltage gain (20 log), dB-to-ratio reverse modes, and cascaded stage totals.
Open Distance Attenuation Calculator Calculate how sound pressure level drops with distance. Covers point, line, and plane sources using the inverse square law for dB attenuation.
Open Doppler Effect Calculator Find the Doppler-shifted frequency, wavelength and percent shift for sound or light. Set the medium or air temperature, pick speed units, and check the Mach number.
Open Frequency Converter Convert frequency between Hz, kHz, MHz, GHz, THz, rpm, rps and angular units (rad/s, deg/s). See the period, pick a target unit, and read the wavelength too.
Open Helmholtz Resonator Calculator Calculate the resonance frequency of a Helmholtz resonator from cavity volume, neck area, and neck length. Supports reverse-solve, end correction, and multiple unit systems.
Open Modulation Calculator (AM, FM, PM) AM, FM, and PM modulation index calculator with modulation depth, Carson's rule bandwidth, AM power distribution, sideband frequencies, and over-modulation status.
Open Reverberation Time Calculator Calculate RT60 reverberation time using Sabine and Eyring formulas. Enter room size and surface materials to get decay time and acoustic targets instantly.
Open Sound Absorption Coefficient Calculator Calculate sound absorption coefficient, total room absorption in sabins, RT60 reverberation time, and required treatment area. Material reference table included.
Open Sound Wavelength Calculator Calculate the wavelength, frequency, or speed of sound in air, water, steel and 10+ other media. Includes period, wave number, temperature presets and hearing-range context.
Open Speed of Sound Calculator Calculate the speed of sound in air, fresh water, or seawater from temperature. Get results in m/s, km/h, ft/s, mph, and knots with step-by-step workings.
Open Speed of Sound in Solids Calculator Calculate longitudinal, shear, and Rayleigh wave speeds in any solid. Choose a material preset or enter custom elastic moduli and density. Shows all formulas.
Open
Quantum Mechanics 15
Bohr Model Calculator Calculate Bohr model energy levels, orbital radius, electron velocity, and photon wavelength for hydrogen-like ions. Covers H, He+, Li2+ with spectral series identification.
Open Compton Scattering Calculator Calculate Compton scattering: wavelength shift, scattered photon energy, recoil electron energy and angle, energy loss fraction, and Klein-Nishina cross section.
Open Compton Wavelength Calculator Calculate the Compton wavelength and reduced Compton wavelength of any particle from its mass. Add a scattering angle to get the wavelength shift and energy transfer.
Open Curie Constant Calculator Calculate the Curie constant C for any paramagnetic material from number density, g-factor and quantum number J. Also finds effective magnetic moment and chi.
Open De Broglie Wavelength Calculator Find the de Broglie wavelength from velocity, kinetic energy or momentum. Pick a particle preset, switch units, and toggle the relativistic correction for fast beams.
Open Fermi Level Calculator Calculate the Fermi level in intrinsic and doped semiconductors. Get carrier concentrations, thermal voltage, and band-edge positions for silicon, germanium, and GaAs.
Open Frequency of Light Calculator Calculate the frequency of light from wavelength, or solve for energy per photon in eV and joules. Instant EM spectrum region, step-by-step math, and reference table.
Open Heisenberg's Uncertainty Principle Calculator Calculate position-momentum or energy-time uncertainty using Heisenberg's principle. Solve for any variable, with worked steps and real particle examples.
Open Hydrogen Energy Levels Calculator Calculate hydrogen and hydrogen-like atom energy levels, transition energy, photon wavelength, and frequency using the Bohr model. Supports H, He+, Li2+ and more.
Open Magnetic Moment Calculator Calculate the magnetic moment of a current loop, solenoid, or coil. Also compute torque in a field, potential energy, and quantum orbital or spin moments.
Open Photoelectric Effect Calculator Calculate photon energy, max kinetic energy, stopping potential, and threshold frequency for the photoelectric effect. 14 preset metals, instant results.
Open Photon Energy Calculator Find photon energy from wavelength, frequency, wavenumber or energy. Get eV, joules, frequency, wavelength, energy per mole, plus photon flux and a spectrum band.
Open Rydberg Equation Calculator Calculate the wavelength, frequency, wavenumber, and photon energy of light from hydrogen and hydrogen-like atoms using the Rydberg equation, with step-by-step math.
Open Stefan-Boltzmann Law Calculator Stefan-Boltzmann law calculator: get radiated power from T, area and emissivity, or reverse-solve for T. Material emissivity presets and Wien peak wavelength included.
Open Wien's Law Calculator Calculate peak emission wavelength from blackbody temperature, or reverse-solve temperature from wavelength. Shows frequency, spectral region, and stellar type.
Open
Astronomy 15
Alien Civilization Calculator Estimate how many alien civilizations exist using the Drake Equation or Copernican model. Get nearest distance, detection probability, and a full worked breakdown.
Open Delta-V Calculator Rocket delta-v calculator using the Tsiolkovsky equation. Solve for delta-v, dry mass, wet mass, or Isp. Propellant presets and common mission delta-v reference table.
Open Earth Orbit Calculator Calculate orbital speed, period, angular velocity, and escape velocity for any Earth orbit altitude. Metric and imperial units with step-by-step math shown.
Open Escape Velocity Calculator Find escape velocity from any planet, moon or star with v = sqrt(2GM/r). Get orbital velocity, surface gravity and mph, switch units, or reverse solve for mass.
Open Exoplanet Discovery Calculator: Transit, Radial Velocity, Habitable Zone Calculate exoplanet properties using transit depth, radial velocity, Kepler orbital period, equilibrium temperature, and habitable zone. Step-by-step math included.
Open Hohmann Transfer Calculator Calculate the two delta-v burns, transfer orbit properties, time of flight, and propellant mass for a Hohmann orbital transfer between any two circular orbits.
Open Kepler's Third Law Calculator Calculate orbital period, semi-major axis, or central body mass using Kepler's third law. Solve any direction, with worked steps and a planet comparison table.
Open Orbital Period Calculator Calculate orbital period, semi-major axis, or central body mass using Kepler's Third Law. Supports satellites, binary stars, planets, and moons with full unit control.
Open Orbital Velocity Calculator Find orbital velocity for circular or elliptical orbits from central mass and radius or a planet preset. Get period, escape velocity and energy with steps.
Open Rocket Equation Calculator Calculate delta-v, mass ratio, propellant mass, or initial mass with the Tsiolkovsky rocket equation, including propellant presets and mission reference budgets.
Open Rocket Thrust Calculator Calculate rocket thrust using F = mdot x ve + Ae(Pe - Pamb). Get momentum thrust, pressure thrust, specific impulse, and thrust-to-weight ratio instantly.
Open Specific Impulse Calculator Calculate rocket specific impulse (Isp), exhaust velocity, thrust, mass flow, and delta-v with the Tsiolkovsky equation, across chemical, ion, and nuclear propulsion.
Open Synodic Period Calculator: Planetary Conjunctions and Oppositions Calculate the synodic period of any planet or moon from two sidereal orbital periods. Solar system presets, worked steps, and a full planetary reference table included.
Open Thrust to Weight Ratio Calculator Calculate thrust-to-weight ratio (TWR) for rockets, aircraft, and drones. Solve for TWR, required thrust, max mass, or net acceleration. Vehicle presets included.
Open UFO Travel Calculator Calculate UFO travel time, Lorentz factor, relativistic time dilation, and kinetic energy for any interstellar distance. Also compare atmospheric city-to-city speeds.
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Energy Work And Power 12
Bullet Energy Calculator Calculate bullet kinetic energy in foot-pounds and joules. Includes hunting suitability guide, cartridge reference table, and metric/imperial unit switching.
Open Elastic Potential Energy Calculator Solve the spring energy formula U = ½·k·x² for energy, spring constant, or displacement. Switch units, see the restoring force, and find the launch speed of a mass.
Open Impact Energy Calculator Calculate impact energy from mass and velocity, drop height, or a Charpy/Izod pendulum test. Metric and imperial units, impact force, and real-world examples.
Open Kinetic Energy Calculator Find kinetic energy from mass and speed, or solve in reverse for mass or velocity. Switch mass, speed and energy units, see momentum and energy conversions.
Open Potential Energy Calculator Find gravitational potential energy from mass, height and g, or reverse solve for any one. Planet gravity presets, metric and imperial units, plus energy equivalents.
Open Power-to-Weight Ratio Calculator Calculate power-to-weight ratio in W/kg, kW/tonne, hp/lb and more. Works for cars, cycling and any engine. See your vehicle or fitness category instantly.
Open Recoil Energy Calculator Calculate firearm free recoil energy (ft-lbf or joules), recoil impulse, and recoil velocity. Enter bullet weight, muzzle velocity, powder charge, and gun weight.
Open Signal-to-Noise Ratio Calculator Calculate signal-to-noise ratio (SNR) in decibels using power, voltage, simple ratio, dB difference, or coefficient of variation. Instant results with worked steps.
Open TNT Equivalent Calculator Convert energy to TNT equivalent mass instantly. Choose from 14 explosives or enter custom values. Includes blast overpressure, damage zones, and worked steps.
Open Watt Converter Convert watts to kilowatts, horsepower, BTU/h, megawatts, dBm and 15 other power units instantly. Shows the formula, worked example, and a full comparison table.
Open Work and Power Calculator Calculate mechanical work, power, force, distance, or time. Supports angle of application, unit switches (metric and imperial), and step-by-step solutions.
Open Work Calculator Calculate work (W = F·d·cosθ) in joules, or reverse-solve for force, distance, or angle. Add a time for power in watts, switch N/lbf/ft/m units, or use velocity change.
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Astrophysics 12
Black Hole Collision Calculator Black hole merger calculator: find final mass, Schwarzschild radii, chirp mass, ISCO peak frequency, radiated energy, and ringdown frequency instantly.
Open Black Hole Temperature Calculator Calculate the Hawking temperature of any black hole from its mass, plus Schwarzschild radius, entropy, luminosity, evaporation time, and peak photon wavelength.
Open Drake Equation Calculator Use the Drake equation to estimate communicating alien civilizations in the Milky Way. Enter all 7 factors and compare optimistic, pessimistic, and 1961 scenarios.
Open Hubble Law Distance Calculator: Recessional Velocity and Cosmic Distance Calculate a galaxy's recessional velocity from its distance or vice versa using Hubble's Law. Adjust the Hubble constant, switch units, and see the step-by-step math.
Open Light Year Calculator Convert light years to km, miles, AU and parsecs - or reverse any unit. Includes step-by-step working, light travel time, and a table of 15 famous cosmic distances.
Open Luminosity Calculator Calculate star luminosity from radius and temperature via the Stefan-Boltzmann law. Get solar luminosities, watts, absolute magnitude, and apparent magnitude instantly.
Open Olbers' Paradox Calculator Calculate the expected night-sky brightness under the infinite static universe model and see exactly how finite universe age and cosmic expansion resolve Olbers' paradox.
Open Parallax Calculator: Stellar Distance from Parallax Angle Calculate stellar distance in parsecs, light-years, and AU from the parallax angle, or reverse-solve the parallax from a known distance. Step-by-step working shown.
Open Radiation Pressure Calculator Calculate radiation pressure from intensity, reflectivity, and angle. Get force, acceleration, delta-v for solar sails, and stellar interior pressure from temperature.
Open Redshift Calculator: Wavelength, Velocity and Cosmological Distance Compute redshift z from wavelength or frequency shifts. Convert z to recession velocity, lookback time, and cosmological distances using the relativistic formula.
Open Schwarzschild Radius Calculator Calculate the Schwarzschild radius (event horizon) for any mass. Enter mass in kg, solar, or Earth masses to get radius, gravitational field, and known-object comparisons.
Open Universe Expansion Calculator Calculate recession velocity, proper distance, comoving distance, and lookback time for any galaxy redshift using the Hubble constant and flat LCDM model.
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Relativity 9
Bug-Rivet Paradox Calculator Bug-Rivet Paradox calculator. Get Lorentz factor, contracted lengths in each frame, the critical speed, and a step-by-step resolution of this relativity paradox.
Open E = mc² Calculator Calculate rest energy from mass using Einstein's E = mc². Choose units, get results in joules, kWh, megatons of TNT, and real-world comparisons.
Open Electron Speed Calculator Calculate electron speed from accelerating voltage or kinetic energy. Compare classical and relativistic results, get the Lorentz factor, momentum, and de Broglie wavelength.
Open Gravitational Time Dilation Calculator Calculate gravitational time dilation using the Schwarzschild formula. Enter mass and radius to find how much slower time flows in a gravitational field versus deep space.
Open Length Contraction Calculator Relativistic length contraction calculator. Enter rest length and velocity, get contracted length, Lorentz factor, and % shrinkage. Presets: ISS, muon, LHC proton.
Open Relativistic Kinetic Energy Calculator Calculate relativistic kinetic energy, Lorentz factor, total energy, rest energy, and relativistic momentum for any mass and velocity up to the speed of light.
Open Space Travel Calculator: Relativistic Time Dilation and Ship Time Calculate relativistic space travel: ship time (proper time), Earth time, max velocity, Lorentz factor, and fuel ratio for any destination under constant acceleration.
Open Time Dilation Calculator Special relativity time dilation: t = t0/sqrt(1 - v2/c2). Pick a velocity unit or preset, reverse-solve the speed, with Lorentz gamma and length contraction.
Open Velocity Addition Calculator Relativistic velocity addition calculator using Einstein's formula. Get the true combined speed, classical comparison, Lorentz factor, and result as a fraction of c.
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Everyday Physics And Experiments 9
Buoyancy Experiment Calculator Calculate buoyant force, check float vs. sink, or find unknown liquid density with the two-liquid interface experiment. Metric and imperial units included.
Open Flat vs. Round Earth Calculator Run three classic experiments, disappearing ships, stick shadows and double sunsets, to see how a round Earth predicts results a flat Earth cannot. Metric or imperial.
Open Hair Diffraction Calculator Measure hair diameter with a laser. Enter wavelength, screen distance, and fringe position. Six solve modes, step-by-step diffraction math, hair-thickness gauge.
Open Immersed Weight Calculator Calculate the immersed weight of any object in 12 common fluids or a custom liquid. Uses Archimedes principle: immersed weight = object weight minus buoyant force.
Open Mass Moment of Inertia Calculator Calculate rotational inertia for 10 rigid-body shapes: spheres, cylinders, rods, disks, and cones. Metric/imperial units, parallel-axis theorem, step-by-step working.
Open Projectile Motion Experiment Calculator Calculate projectile range, max height, time of flight, and launch velocity from experiment measurements. Supports metric and imperial units with step-by-step math.
Open Smartphone Projector Calculator Calculate image distance, magnification, and projected screen size for your DIY smartphone projector from lens focal length and phone position.
Open Sun Angle Calculator Calculate solar elevation angle, azimuth, declination, hour angle, shadow length, air mass, sunrise, sunset and solar noon for any location and time.
Open Sunrise Sunset Calculator Calculate exact sunrise, sunset, solar noon, day length, and civil, nautical and astronomical twilight times for any location and date.
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Dynamics 1
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What Physics Calculators Are Used For
Physics calculators handle the quantitative side of mechanics, kinematics, electricity, thermodynamics, and optics. Students use them to verify homework and exam answers. Engineers use them for back-of-the-envelope estimates before running full simulations. Hobbyists use them to design circuits, analyze projectile paths, or understand heat transfer in a home project. In every case, the goal is to translate a physical scenario into numbers that can be checked, optimized, or communicated clearly.
Common Uses and Real-Number Examples
- Projectile motion and kinematics. If you launch a ball at 20 meters per second at a 45-degree angle, a kinematics calculator shows it will reach a maximum height of about 10.2 meters and travel a horizontal distance of roughly 40.8 meters before landing, assuming no air resistance. You can vary the angle to see how 30 degrees or 60 degrees change the range.
- Newton's second law and force. F = ma means force equals mass times acceleration. If a 70 kg person accelerates from rest to 5 m/s in 2 seconds, the net force required is 70 times (5 divided by 2) = 175 newtons. A force calculator handles unit conversions between newtons, pounds-force, and dynes automatically.
- Ohm's law and circuit basics. In a circuit with 12 volts across a 4-ohm resistor, current equals voltage divided by resistance = 3 amperes. Power dissipated equals voltage times current = 36 watts. Ohm's law calculators solve for any one of the four quantities when you supply the other three.
- Kinetic and potential energy. A 2 kg object moving at 10 m/s has kinetic energy of 0.5 times 2 times 10² = 100 joules. The same object resting at 5 meters above the ground has potential energy of 2 times 9.8 times 5 = 98 joules. Energy calculators confirm conservation checks in textbook problems.
Key Concepts in Plain Language
Most introductory physics comes down to a handful of core relationships: force, mass, and acceleration (Newton's second law); voltage, current, and resistance (Ohm's law); work, force, and displacement (W = Fd); and energy conservation. These relationships are linear, meaning doubling one variable doubles the result, which makes estimation straightforward once you know the formula. Thermodynamics adds concepts like heat transfer, entropy, and the ideal gas law (pressure times volume equals the number of moles times the gas constant times temperature).
What to Look For When Using These Tools
Physics calculations are extremely sensitive to units. Mixing meters with feet, or kilograms with pounds, without converting first will produce wrong answers. Always confirm the unit system a calculator uses at the start, and stick with SI units (meters, kilograms, seconds, joules, watts) when possible to avoid conversion errors. Also check whether a result is physically plausible: a force of 10,000 newtons to push a bicycle is a red flag that something in the input is off.