Gallons to Liters formula
1 US gallon = 3.785411784 litres, and 1 litre = 0.2641720524 US gallons. 231 cubic inches, exactly 3.785411784 litres.
Gallons to Liters chart
| US gallons (gal (US)) | Litres (l) |
|---|---|
| 0.25 | 0.9464 |
| 0.5 | 1.8927 |
| 1 | 3.7854 |
| 2 | 7.5708 |
| 3 | 11.3562 |
| 4 | 15.1416 |
| 5 | 18.9271 |
| 6 | 22.7125 |
| 7 | 26.4979 |
| 8 | 30.2833 |
| 10 | 37.8541 |
| 12 | 45.4249 |
| 15 | 56.7812 |
| 20 | 75.7082 |
| 25 | 94.6353 |
| 30 | 113.5624 |
| 40 | 151.4165 |
| 50 | 189.2706 |
| 55 | 208.1976 |
| 75 | 283.9059 |
| 100 | 378.5412 |
Values are rounded to 4 decimal places. The converter above shows more precision.
Worked examples
A 5-gallon water-cooler bottle
5 gal (US) × 3.785411784 = 18.9271 l
5 US gallons = 18.9271 litres. About 18.9 litres, which is why office water bottles outside the US are often sold as 18.9 L or 19 L.
A 15-gallon fuel tank
15 gal (US) × 3.785411784 = 56.7812 l
15 US gallons = 56.7812 litres. About 56.8 litres. At a pump that charges by the litre, multiply the price per litre by 56.8 to cost a full tank.
Converting US gallons to litres in real life
US product sizes are often whole gallons: milk jugs, paint cans, water-cooler bottles, aquariums, fuel cans and pool chemicals. Anyone outside the US who buys equipment rated in gallons, or follows an American guide to dosing a tank or mixing a solution, needs the size in litres.
Make sure you know which gallon you have. US sources use the US gallon (3.785 L); British and some older Canadian sources use the imperial gallon (4.546 L). A "5-gallon" bucket in a US store is 18.9 L, but 5 imperial gallons is 22.7 L. To go the other way, use liters to gallons.