Imperial & US Customary Units
Units shared by the British imperial and US customary systems, fixed in metric terms by the 1959 international yard and pound agreement. 18 units are listed.
| Unit | Symbol | Quantity | Value in SI |
|---|---|---|---|
| Inch | in | Length | 25.4 mm (exact) |
| Foot | ft | Length | 0.3048 m (exact) |
| Yard | yd | Length | 0.9144 m (exact) |
| Mile | mi | Length | 1609.344 m (exact) |
| Fathom | ftm | Length | 1.8288 m (exact) |
| Chain | ch | Length | 20.1168 m (exact) |
| Rod | rd | Length | 5.0292 m (exact) |
| Furlong | fur | Length | 201.168 m (exact) |
| Hand | hh | Length | 101.6 mm (4 inches, exact) |
| Acre | ac | Area | 4046.8564224 m² (exact) |
| Pound | lb | Mass | 0.45359237 kg (exact) |
| Ounce | oz | Mass | 28.349523125 g (exact) |
| Grain | gr | Mass | 64.79891 mg (exact) |
| Pound-force | lbf | Force | 4.4482216152605 N (exact) |
| Pound per square inch | psi | Pressure | ≈ 6894.757 Pa |
| British thermal unit | BTU | Energy | ≈ 1055.056 J (International Table) |
| Mechanical horsepower | hp | Power | 550 ft·lbf/s ≈ 745.7 W |
| Degree Fahrenheit | °F | Temperature | °F = °C × 9/5 + 32 |