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Approximate Conversions from Metric to U.S. Customary Measures
The numerical value of the units in the When You Know column are multiplied by the approximate unit conversion factor found in the Multiply By column to obtain a numerical value for the units listed in the To Find Column. For example:
| When You Know | Multiply By | To Find |
|---|---|---|
| 20 m | 1.09 | approximately 21.8 yd |
Length
| Symbol | When You Know | Multiply By | To Find | Symbol |
|---|---|---|---|---|
| mm | millimeter | 0.04 | inch | in |
| cm | centimeter | 0.39 | inch | in |
| m | meter | 3.28 | foot | ft |
| m | meter | 1.09 | yard | yd |
| km | kilometer | 0.62 | mile | mi |
Area
| Symbol | When You Know | Multiply By | To Find | Symbol |
|---|---|---|---|---|
| cm² | square centimeters | 0.16 | square inch | in² |
| m² | square meter | 1.20 | square yard | yd² |
| km² | square kilometer | 0.39 | square mile | mi² |
| ha | hectare (10,000 m2) | 2.47 | acre |
Mass (weight)
| Symbol | When You Know | Multiply By | To Find | Symbol |
|---|---|---|---|---|
| g | gram | 0.04 | ounce | oz |
| kg | kilogram | 2.20 | pound | lb |
| metric ton (1,000 kg) | 1.10 | short ton |
Volume
| Symbol | When You Know | Multiply By | To Find | Symbol |
|---|---|---|---|---|
| mL | milliliter | 0.03 | fluid ounce | fl oz |
| mL | milliliter | 0.06 | cubic inch | in³ |
| L | liter | 2.11 | pint, liquid | pt |
| L | liter | 1.06 | quart, liquid | qt |
| L | liter | 0.26 | gallon | gal |
| m³ | cubic meter | 35.31 | cubic foot | ft³ |
| m³ | cubic meter | 1.31 | cubic yard | yd³ |
Temperature (exact)
| Symbol | When You Know | Calculation | To Find | Symbol |
|---|---|---|---|---|
| °C | degree Celsius | multiply 1.8, then add 32 | degree Fahrenheit | °F |
| K | Kelvin | subtract 273.15 | degree Celsius | °C |
U.S. Customary to Metric Conversions
Unit conversion is a multi-step process that involves multiplication or division by a numerical factor; selection of the correct number of significant digits; and rounding. Accurate unit conversions are obtained by selecting an appropriate conversion factor (a ratio which converts one unit of measure into another without changing the quantity).
Note: These approximate conversion factors are published as NIST SP 365, Metric Conversion Card. Copies of this publication can be requested by contacting theSI [at] nist.gov (theSI[at]nist[dot]gov) or made using the OWM Contacts System.
Resources
Contacts
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Metric Program