How Many Liters In A Gallon? (With Conversion Charts)

There are 3.79 liters in a US customary gallon, while there are 4.55 liters in a British imperial gallon. Liters are part of the metric system, which is used across most of the world. On the other hand, gallons are part of the US customary system of measurement and the British imperial system of measurement.

Liters & Gallons Converter

Calculate how many liters are in a gallon (or vice versa) with this conversion calculator. Enter the amount, select which conversion you want, and then click convert.

Although the US and British systems are similar and both use gallons, they are not the same. When dealing with gallons it’s important to know if you’re working with US or British gallons, especially if you’re abroad or following an international recipe. So here’s what you need to know about gallons, liters, and how to convert them.

What is a Liter?

A liter is a unit of volume from the metric system and is abbreviated as l, L, or ℓ. A liter is defined as being equal to one cubic decimeter or one thousandth of a cubic meter. One liter of water weighs almost exactly 1 kilogram.

The liter first came into use during the French Revolution, when the revolutionaries sought not only to upend centuries-old institutions such as the monarchy, but also to reform their archaic system of weights and measures and create a standardized system of measurement “for all people, for all time”.¹ And remarkably, that’s exactly what they did. Today the metric system has reached all four corners of the globe, and been adopted by every nation bar three – the United States (US), Liberia, and Myanmar.

The word liter, is spelled litre in many countries, and comes from the Roman libra and Greek litra, which was an ancient unit of money and weight.²

What is a Gallon?

A gallon is a measure of volume that is equivalent to 4 quarts or 8 pints. It first came into use in 15ᵗʰ century England as a unit for measuring for wine and beer. The gallon dates back to the French galon or jalon, which was an old liquid measure that was around the same size as a modern gallon.

The word gallon is derived from the Latin word galleta meaning jug or bucket, and also “measure for wine”. However, the word gallon may ultimately be Celtic in origin.³⁴

Gallons are used in the imperial system of measurement (the system of measurement from the United Kingdom) and the US customary system (the system of measurement in the United States). Although both systems have gallons, they are not the same size.

That means there is more than one type of gallon. So the number of liters in a gallon will depend on the type of gallon.

Types of Gallons

There are two main types of gallon for measuring liquids around the world.

US customary gallon (also called US liquid gallon). One gallon is equal to 3.785411784 liters.⁵ It is part of the US customary system and chiefly used in the United States, but also in several other countries where it is the standard petrol unit.
Imperial gallon. One gallon is equal to 4.546092 liters.⁶ Used in the United Kingdom (UK) and several Caribbean nations with historic ties to the UK. An imperial gallon is about 20 % larger than the U.S. liquid gallon.

There is another type of gallon in the United States called the US dry gallon, which has mostly fallen out of use and is not part of the US customary system.

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