gallons to liters
1 US gallon equals 3.7854 liters. Formula: liters = gallons × 3.78541.
= 56.7812 L
Other direction: liters to gallons
Formula
liters = gallons × 3.78541
Example: 15 gal = 56.7812 L.
When you need gallons to liters
US fuel purchases, milk jugs, and drum sizes come in gallons. Multiplying by 3.785 gives liters: a 15-gallon fill-up is about 56.8 L, a gallon of milk is 3.79 L, and the classic 55-gallon drum holds about 208 L.
The US gallon is defined as exactly 231 cubic inches, which works out to exactly 3.785411784 liters — so the conversion is exact, if long-winded. For estimates, 1 gallon ≈ 3.8 L works fine.
Common gal to L values
| US gallons (gal) | Liters (L) |
|---|---|
| 0.5 | 1.8927 |
| 1 | 3.7854 |
| 2 | 7.5708 |
| 5 | 18.9271 |
| 10 | 37.8541 |
| 15 | 56.7812 |
| 20 | 75.7082 |
| 55 | 208.2 |
FAQ
How many liters are in a gallon?
One US gallon is exactly 3.785411784 liters — call it 3.8 L for estimates. An imperial gallon is larger at about 4.546 L.
How many liters is a 55-gallon drum?
A 55-US-gallon drum holds about 208.2 liters.