Gallons to Liters (gal to L)
1 gal = 3.78541 L
To convert US gallons to liters: liters = US gallons × 3.785411784
| US gallons | liters |
|---|---|
| 1 gal | 3.785 L |
| 2 gal | 7.571 L |
| 2.5 gal | 9.464 L |
| 3 gal | 11.36 L |
| 5 gal | 18.93 L |
| 10 gal | 37.85 L |
| 15 gal | 56.78 L |
| 20 gal | 75.71 L |
| 50 gal | 189.3 L |
| 55 gal | 208.2 L |
| 100 gal | 378.5 L |
| 125 gal | 473.2 L |
A US gallon is exactly 3.785411784 liters. The UK (imperial) gallon is larger at 4.54609 liters — about 20% more — so check which gallon you have.
Formula
liters = US gallons × 3.785411784
Example: 5 US gallons = 18.9271 liters.
Gallons to Liters chart
| US gallons | liters |
|---|---|
| 0.5 | 1.89271 |
| 1 | 3.78541 |
| 2 | 7.57082 |
| 5 | 18.9271 |
| 10 | 37.8541 |
| 12 | 45.4249 |
| 15 | 56.7812 |
| 20 | 75.7082 |
| 25 | 94.6353 |
| 30 | 113.562 |
| 40 | 151.416 |
| 50 | 189.271 |
| 55 | 208.198 |
| 75 | 283.906 |
| 100 | 378.541 |
Good to know
Fuel economy and tank sizes are where the two gallons get mixed up: a 15-gallon US tank holds 56.8 L; a 15-gallon UK tank would hold 68.2 L. Miles per gallon figures differ for the same reason. Motor oil comes in quarts — convert quarts to gallons by dividing by 4, then to liters here.
Aquariums: a 20-gallon tank is 75.7 L and a 55-gallon tank is 208 L of gross volume, before gravel and decor. A gallon of fresh water weighs about 8.33 lb; for other liquids, the density converter turns lb/gal into kg/m³ or g/mL.
Converting fuel economy rather than a fuel volume? L/100km to mpg handles the reciprocal maths.
Read next: US vs UK gallons to liters: the 20% imperial gap explained
Frequently asked questions
How many liters in a gallon?
3.785 L in a US gallon; 4.546 L in a UK (imperial) gallon.
How many liters is 5 gallons?
5 US gallons is 18.93 L.
Is a UK gallon bigger than a US gallon?
Yes, by about 20%: 4.546 L vs 3.785 L.