Gallon – definition and meaning

A gallon, or GL, is a unit of liquid volume. However, the term represents different volumes in British and American English.

In American English, 1 GL equals 231 cubic inches, 3.78 liters, 0.13 cubic feet, and weighs 8.33 pounds.

In British English, 1 GL equals 277.42 cubic inches, 4.55 liters, 0.15 cubic feet, and weighs 10 pounds.

One American GL equals 0.83 of a British GL.

People can also say Imperial Gallon when using the British meaning of the term.

The English Oxford Living Dictionaries, says the following about the term:

“1. (British) A unit of liquid or dry capacity equal to eight pints or 4.55 liters. 2. (US) A unit of liquid capacity equal to 3.79 liters.”

If you read that gas (UK: petrol) is now selling at below $2 a gallon in the US, remember that that is a different amount in the UK.

Etymology of gallon

Etymology refers to the origin of words. It is also the study of how words and their meanings have evolved.

According to, as an English measure of capacity, the term emerged in the late thirteenth century in England. It meant four quarts. It came from the Old North French word Galon, which corresponded to the Old French word Jalon.

The Old French word came from the Medieval Latin Galleta, which meant ‘bucket’ or ‘pail.’ It was also a measure of wine. The Gaulish word Galla meant ‘vessel.’ However, where the Gaulish word came from is unclear.

Gallon - definition of British and American meanings
The American gallon is smaller than the Imperial (British) gallon.

Usage of gallon today

Most British and Irish people use the term ‘gallon’ much less now than before. It is no longer an official volume of measure in the two countries. However, people still use it in conversations.

In fact, in the UK and Ireland, when talking about car mileage, people still say MPG or miles per gallon.

Filling stations in the British Isles quote their prices in liters.

People in most countries, however, where the term has never been used, understand what gallons are.

If you want to visualize a gallon, imagine eleven regular-sized cans of coke. You could also imagine 8 pints of beer.

Ten-gallon hat - definition and three actors wearing one
The Stetson company is the most famous ‘ten-gallon hat’ company. Actors such as John Wayne, Dan Blocker, and Tim McCoy were famous for their Stetson hats. Some people say the term is a corruption of the Spanish term ‘tan galán,’ which means ‘so gallant.’ ‘Un sombrero tan galán,’ means ‘such a gallant (fine) hat.’

Gallons of..

We also use the term in idiomatic expressions. ‘Gallons of‘ means ‘a lot of.’

For example, if I say that we have ‘gallons of wine,’ it means we have a lot of wine.

In 1925, the term ‘ten-gallon hat‘ emerged. It refers to a large cowboy hat, such as the ‘Stetson.’ In fact, the Stetson hat company boasted that its hats were so waterproof that you could use them as buckets.