Convert US Gallons to Liters
US gallons to liters is the conversion for turning an American volume into metric — handy for fuel, water use, or any spec written in gallons. One US gallon is exactly 3.785411784 liters, so the number gets bigger going from gallons to liters because a liter is the smaller unit.
US Gallons to Liters conversion table
| US Gallons (gal) | Liters (L) |
|---|---|
| 1 | 3.785412 |
| 2 | 7.570824 |
| 3 | 11.356235 |
| 5 | 18.927059 |
| 10 | 37.854118 |
| 20 | 75.708236 |
| 50 | 189.270589 |
| 100 | 378.541178 |
| 500 | 1,892.705892 |
| 1,000 | 3,785.411784 |
The formula
To convert US gallons to liters, multiply the volume in US gallons by 3.785411784:
liters = US gallons × 3.785411784
A worked example
A typical US car fuel tank holds about 15 US gallons. In liters:
15 × 3.785411784 = 56.78 L
So that tank is a little under 57 liters.
Why the number is exact
The US gallon isn't a rough figure — it's pinned to 231 cubic inches exactly, and since the inch is defined in metric terms, the gallon comes out to exactly 3.785411784 liters. Every conversion is precise; any rounding you see is only in the display.
When you'll use it
Converting American fuel-tank or fuel-economy figures to metric, sizing US-spec water heaters and tanks in liters, translating US recipe volumes, and comparing appliance capacities across metric and American labeling.
Frequently asked questions
How many liters are in a US gallon?
Exactly 3.785411784 liters. This value is exact by definition — a US gallon is defined as 231 cubic inches, which works out to that many liters precisely. Note this is the US gallon, not the larger UK one.
How is a US gallon different from an imperial gallon?
A US gallon is 3.785 liters; a UK (imperial) gallon is about 4.546 liters, roughly 20% bigger. So '10 gallons' means quite different amounts depending on which side of the Atlantic you're on. This page uses US gallons.
Is there a quick way to estimate gallons to liters?
Multiply by about 3.8, or just under 4. So 5 US gallons is roughly 19 liters, and 10 gallons is close to 38 liters. Use the exact factor when it matters.