The imperial (UK) gallon, now defined as exactly 4.54609 litres (about 277.42 cubic inches), is used in some Commonwealth countries and was originally based on the volume of 10 pounds (approximately 4.54 kg) of water at 62 °F (17 °C). The imperial fluid ounce is defined as 1⁄160 of an imperial gallon; there are four quarts in a gallon, two pints in a quart, and 20 Imperial fluid ounces in an imperial pint.
| Definition | Relation to SI units |
|---|---|
≡ 4.54609 L |
| US legal cup | pipe | drop (imperial) | pony | imperial minim | fluid scruple | petaliter | hectoliter |
|---|---|---|---|---|---|---|---|
| 1 | 0.0005032 | 2,432.6839108 | 10.8204873 | 4,054.4731847 | 202.7236592 | 2.4 × 10-16 | 0.0024 |
| 1,987.3411866 | 1 | 4,834,572.929895 | 21 504 | 8,057,621.5498223 | 402,881.0774932 | 4.76961884784 × 10-13 | 4.7696188 |
| 0.0004111 | 2.0684350293206 × 10-7 | 1 | 0.0044480 | 1.6666667 | 0.0833333 | 9.86564670138 × 10-20 | 9.86564670138 × 10-7 |
| 0.0924173 | 4.6502976190476 × 10-5 | 224.8220299 | 1 | 374.7033831 | 18.7351692 | 2.2180147171875 × 10-17 | 0.0002218 |
| 0.0002466 | 1.2410610175928 × 10-7 | 0.6000000 | 0.0026688 | 1 | 0.0500000 | 5.91938802083 × 10-20 | 5.91938802083 × 10-7 |
| 0.0049328 | 2.482122035173 × 10-6 | 12.0000000 | 0.0533756 | 20.0000000 | 1 | 1.18387760416 × 10-18 | 1.18387760416 × 10-5 |
| 4.1666666666667 × 1015 | 2 096 603 590 144 | 1.0136182961631 × 1019 | 4.5085363602457 × 1016 | 1.6893638269379 × 1019 | 8.4468191347325 × 1017 | 1 | 10 000 000 000 000 |
| 416.6666667 | 0.2096604 | 1,013,618.2961631 | 4,508.5363602 | 1,689,363.8269379 | 84,468.1913473 | 1.0 × 10-13 | 1 |
| Symbol | Definition |
|---|---|
| ≡ | exactly equal |
| ≈ | approximately equal to |
| = | equal to |
| digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |
| 1 imperial gallons | = 0.00454609 cubic meters |
| 2 imperial gallons | = 0.00909218 cubic meters |
| 3 imperial gallons | = 0.01363827 cubic meters |
| 4 imperial gallons | = 0.01818436 cubic meters |
| 5 imperial gallons | = 0.02273045 cubic meters |