Convert US Gallons to Liters

About converting US Gallons to Liters

US Gallons (gal (US)) and Liters (L) are both units of volume, so converting between them is a single multiplication: multiply your US Gallons figure by 3.7854. Ten US Gallons comes to 37.8541 Liters, and a hundred works out at 378.5412 Liters.

Rule of thumb: going from US Gallons to Liters multiplies, so the figure always grows — one US Gallon is already 3.7854 Liters. If your answer came out smaller, you have the conversion the wrong way round.

What is an US Gallon?

The US gallon is defined as exactly 231 cubic inches, a figure inherited unchanged from the old English wine gallon. When Britain overhauled its measures in 1824 and adopted a new imperial gallon, the United States simply kept the wine gallon it already had — and that single decision is the root of the entire US-versus-imperial mess that still catches people out today. The US gallon is roughly a fifth smaller than the imperial one, which means American and British fuel-economy figures are not comparable even though both are quoted in miles per gallon.

What is a Liter?

The liter is not, strictly speaking, an SI unit — it is merely accepted for use alongside SI, and is defined as exactly one cubic decimetre: the volume of a cube ten centimetres on a side. That pedantic status has done nothing to slow it down, since it is how most of the world buys fuel, milk, paint and soft drinks. Both L and l are accepted symbols, but the capital L is preferred in the United States and increasingly elsewhere, because a lowercase l in most typefaces is almost indistinguishable from the digit 1 — a genuine hazard on a dosage label.

To put both in perspective: a typical American milk jug holds one US gallon, while a large bottle of soda holds two liters.

The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the Liters to US Gallons converter, or browse all Volume converters.