Metric to Standard Converter
Convert any metric measurement to US customary (standard) units - or reverse the direction - across five categories: length, weight, volume, area and temperature. Select the category, choose your starting unit, enter a value, and every equivalent appears instantly. Exact NIST conversion factors are used throughout.
Formula
Worked example
1 meter to US standard: 1/0.0254 = 39.3701 in; 39.3701/12 = 3.28084 ft; 3.28084/3 = 1.09361 yd; 1/1609.344 = 0.000621 mi.
What is the metric system and what is US standard?
The metric system (formally the International System of Units, SI) is the global scientific standard. It is base-10: length uses kilometers, meters, centimeters and millimeters; mass uses kilograms and grams; volume uses liters and milliliters. The United States uses a parallel system called US customary - or "standard" in everyday speech - which evolved from English units and uses inches, feet, yards and miles for length; pounds and ounces for mass; and teaspoons, cups, pints, quarts and gallons for volume. Because the two systems use different fundamental base values rather than simply moving a decimal point, converting between them requires fixed multiplication factors derived from the exact SI definitions.
How to use this converter
Select a category (length, weight, volume, area or temperature), choose the direction (metric to US standard or the reverse), select the unit your measurement is already in from the Input unit list, and type your value. Every equivalent in the target system appears instantly. The "Show your work" panel breaks down each conversion step with your actual numbers and the exact factor used. You can switch direction at any time to reverse a conversion without re-entering anything.
Length, weight and volume: how the math works
Length: the inch is defined as exactly 25.4 mm, which fixes all other length factors. One foot = 12 in = 0.3048 m; one yard = 3 ft = 0.9144 m; one mile = 5280 ft = 1609.344 m exactly. Weight: one pound (avoirdupois) = 0.45359237 kg exactly; one kilogram = 2.20462 lb; one metric tonne = 1000 kg = 1.10231 US short tons. Volume: one US gallon = 3.785411784 L exactly; one liter = 33.814 fl oz = 4.22675 cups = 2.1134 pints = 1.0567 quarts = 0.26417 gallons. Temperature: Fahrenheit = Celsius * 9/5 + 32 (non-linear, so it cannot be expressed as a simple multiplier).
Area and temperature conversions
Area: one square meter = 10.7639 sq feet; one hectare (10 000 m2) = 2.47105 acres; one square kilometer = 0.38610 sq miles. These follow from the linear length definitions squared. Temperature is the only non-linear category: Fahrenheit = Celsius * 9/5 + 32, so the scale stretches and shifts. Absolute temperature is measured in Kelvin (SI) or Rankine (US customary): Kelvin = Celsius + 273.15; Rankine = Fahrenheit + 459.67. To go from Kelvin to Rankine, multiply by 9/5.
Common metric to US standard conversion factors
| Metric unit | US standard unit | Factor (metric x factor) |
|---|---|---|
| 1 millimeter (mm) | inches (in) | 0.039370 |
| 1 centimeter (cm) | inches (in) | 0.39370 |
| 1 meter (m) | feet (ft) | 3.28084 |
| 1 meter (m) | yards (yd) | 1.09361 |
| 1 kilometer (km) | miles (mi) | 0.62137 |
| 1 gram (g) | ounces (oz) | 0.035274 |
| 1 kilogram (kg) | pounds (lb) | 2.20462 |
| 1 metric tonne (t) | short tons | 1.10231 |
| 1 milliliter (mL) | fluid ounces (fl oz) | 0.033814 |
| 1 liter (L) | gallons (gal) | 0.26417 |
| 1 liter (L) | cups | 4.22675 |
| 1 sq meter (m2) | sq feet (ft2) | 10.7639 |
| 1 hectare (ha) | acres | 2.47105 |
| C to F | Fahrenheit | C * 9/5 + 32 |
Multiply the metric value by the factor shown to get the US standard value. Factors are exact or carry at least 6 significant figures.
Frequently asked questions
What is the difference between metric and US standard (imperial) units?
Metric units follow the SI standard and are base-10: kilometers, meters, centimeters and millimeters for length; kilograms and grams for mass; liters and milliliters for volume. US customary (standard) units use inches, feet, yards and miles for length; pounds and ounces for mass; and cups, pints, quarts and gallons for volume. Because the two systems have different fundamental definitions, converting requires fixed multiplication factors rather than moving a decimal point.
How do I convert meters to feet?
Multiply meters by 3.28084 to get feet. For example, 5 m = 5 * 3.28084 = 16.4042 ft. The conversion is exact: 1 foot = 0.3048 m by SI definition, so 1 m = 1/0.3048 = 3.280839895... ft.
How do I convert kilograms to pounds?
Multiply kilograms by 2.20462. For example, 10 kg = 22.0462 lb. The exact definition is 1 lb = 0.45359237 kg, so 1 kg = 2.20462262... lb. To reverse, divide pounds by 2.20462.
How do I convert Celsius to Fahrenheit?
Use F = C * 9/5 + 32. For 20 degC: 20 * 1.8 + 32 = 68 degF. Key reference points: 0 degC = 32 degF (water freezes), 100 degC = 212 degF (water boils at sea level), 37 degC = 98.6 degF (normal body temperature). This is the only non-linear conversion in this tool.
How many liters are in a US gallon?
One US gallon is exactly 3.785411784 liters. One liter is about 0.26417 US gallons. Note that the UK imperial gallon is larger at 4.54609 liters. This calculator always uses the US gallon definition.
Can I convert standard to metric with this tool?
Yes. Set the Direction to "US standard to metric" and select the unit you are starting from (feet, pounds, gallons, Fahrenheit, etc.). The calculator converts your value to all common metric equivalents using the same exact NIST factors in reverse.