Gallons to Liters Converter
Convert US gallons (gal) to liters (L) instantly. Type a value — the result updates as you type, and the swap button converts the other way.
Gallons to Liters formula
L = gal × 3.785411784
1 US gallon = 3.79 liters · 1 liter = 0.2642 US gallons
To convert US gallons to liters, multiply the value by 3.785411784. For example, 5 gal:
L = 5 × 3.785411784L = 18.927059
So 5 gal = 18.93 L.
Mental math shortcut
Quick mental estimate: multiply by 3.8. For 5 gal that gives about 19 L — within 1% of the exact answer. Use the exact formula when precision matters.
Gallons to Liters conversion table
Liters back to Gallons
The same values converted the other way, rounded for everyday use:
| Liters | US gallons |
|---|---|
| 1.89 L | 0.4993 gal |
| 3.79 L | 1 gal |
| 7.57 L | 2 gal |
| 11.36 L | 3 gal |
| 18.93 L | 5 gal |
| 37.85 L | 10 gal |
| 56.78 L | 15 gal |
| 75.71 L | 20 gal |
About the units
US gallons (gal)
A US gallon is 128 US fluid ounces, exactly 3.785411784 liters. (The UK imperial gallon is 4.546 liters.)
Liters (L)
A liter is 1,000 milliliters (one cubic decimeter). It is the standard metric unit for drinks, fuel and containers.
Frequently asked questions
How many liters are in a US gallon?
One US gallon equals 3.79 liters.
What is 5 Gallons in Liters?
5 gal = 18.93 L.
How do I convert Liters back to Gallons?
Divide the liters by 3.785411784. Or use the Liters to Gallons converter.