Gallons to Liters Calculator

Convert US gallons to liters for fuel, aquariums, water storage, cleaning concentrates, and product labels. The form has one input, Gallons, and returns Liters rounded to two decimal places.

How to use this calculator

Enter a nonnegative volume in gallons. The calculator treats the input as US gallons, not imperial gallons, then multiplies by the liter equivalent. If you need a broader set of volume units, use the volume converter. For cooking-sized amounts, the milliliters to cups calculator may be more convenient.

Conversion formula

One US gallon equals 3.785411784 liters. To convert gallons to liters, multiply gallons by 3.785411784. To convert liters to gallons, divide liters by the same number.

The form uses the practical factor 3.78541:

$liters = gallons \times 3.78541$

Worked example

For 12 gallons:

$12 \times 3.78541 = 45.42492$

The calculator displays 45.42 L.

Common gallon to liter values

When comparing fuel use internationally, combine this volume conversion with the fuel economy converter.