Gallons to liters

The exact conversion

This page converts the US liquid gallon, the gallon on American gas pumps, milk jugs, and aquarium labels. It is defined as exactly 3.785411784 liters, which is 231 cubic inches. It is not the British imperial gallon of 4.54609 liters. Using the imperial gallon here would overstate the volume by about 20%. A US gallon is a bit under 3.8 liters. Fifteen US gallons, a modest car tank, is 56.781 liters.

The formula used above is L = gal × 3.785412. Both boxes stay in step, so you can start from either unit. Results are rounded for display; the factor itself is the legal definition, not a rounded shortcut.

Worked examples

Each line is the same formula with a new starting number. You can match it against the converter by typing the value on the left.

• 1 US gallon: 1 × 3.785412 = 3.7854 liters.
• 15 US gallons: 15 × 3.785412 = 56.7812 liters.
• 55 US gallons: 55 × 3.785412 = 208.1976 liters.

Where the rounding matters

Fuel prices need the same factor. A price per gallon divided by 3.785411784 is the price per liter. At $3.50 a gallon, that is $0.92 a liter, because 3.50 ÷ 3.785411784 = 0.9246. A 55-gallon drum is 208.198 liters, the figure people round to 208 liters. A 16-gallon fuel can is 60.567 liters. For cooking, a US gallon is 128 US fluid ounces, and this page stays with gallons and liters rather than cups.

Multiply, do not divide, when you start from gallons: the liter number is almost four times the gallon number. If you got a smaller number, you converted liters to gallons instead. The imperial gallon still appears on some UK and Canadian labels. If the label says “imp gal” or the product is from Britain, do not use 3.785. This converter will say so in the result line by calling the unit a US gallon.

Conversion table: gallons to liters