| Quantity | U.S. Customary | Metric | From U.S.
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| | Unit Name | Abbreviation | Unit Name | Abbreviation | | |
| Area | sq. inch | in2 | sq. millimeters | mm2 | 645.16 | 0.001550 |
| | | sq. centimeters | cm2 | 6.452 | 0.155 |
| sq. foot | ft2 | sq. meter | m2 | 0.0929 | 10.764 |
Fuel
Consumption | pounds per
horsepower hour | lb/hp-hr | grams per kilowatt hour | g/kW-hr | 608.277 | 0.001645 |
Fuel
Performance | miles per gallon | mpg | kilometers per liter | km/l | 0.4251 | 2.352 |
| gallons per mile | gpm | liters per kilometer | l/km | 2.352 | 0.4251 |
| Force | pounds force | lbf | Newton | N | 4.4482 | 0.224809 |
| Length | inch | in | millimeters | mm | 25.40 | 0.039370 |
| foot | ft | millimeters | mm | 304.801 | 0.00328 |
| Power | horsepower | hp | kilowatt | kW | 0.746 | 1.341 |
| Pressure | pounds force per
sq. inch | psi | kilopascal | kPa | 6.8948 | 0.145037 |
| inches of mercury | in Hg | kilopascal | kPa | 3.3769 | 0.29613 |
| inches of water | in H2O | kilopascal | kPa | 0.2488 | 4.019299 |
| inches of mercury | in Hg | millimeters of
mercury | mm Hg | 25.40 | 0.039370 |
| inches of water | in H2O | millimeters of water | mm H2O | 25.40 | 0.039370 |
| bars | bars | kilopascals | kPa | 100.001 | 0.00999 |
| bars | bars | millimeters of
mercury | mm Hg | 750.06 | 0.001333 |
| Temperature | fahrenheit | °F | centigrade | °C | (°F-32) ÷1.8 | (1.8 x °C) +32 |
| Torque | pound force per foot | ft-lb | Newton-meter | N•m | 1.35582 | 0.737562 |
| pound force per inch | in-lb | Newton-meter | N•m | 0.113 | 8.850756 |
| Velocity | miles/hour | mph | kilometers/hour | kph | 1.6093 | 0.6214 |
Volume:
liquid
displacement | gallon (U.S.) | gal. | liter | l | 3.7853 | 0.264179 |
| gallon (Imp*) | gal. | liter | l | 4.546 | 0.219976 |
| cubic inch | in3 | liter | l | 0.01639 | 61.02545 |
| cubic inch | in3 | cubic centimeter | cm3 | 16.387 | 0.06102 |
| Weight (mass) | pounds (avoir.) | lb | kilograms | kg | 0.4536 | 2.204623 |
| Work | British Thermal Unit | BTU | joules | J | 1054.5 | 0.000948 |
| British Thermal Unit | BTU | kilowatt-hour | kW-hr | 0.000293 | 3414 |
| horsepower hours | hp-hr | kilowatt-hour | kW-hr | 0.746 | 1.341 |
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