How Many Liters Are in a Gallon?

It depends on which gallon you mean, because there are two:

• 1 US gallon = 3.785 liters (3.78541 L to be precise)
• 1 UK (imperial) gallon = 4.546 liters (4.54609 L to be precise)

The US gallon is the smaller of the two, which is why the same "1 gallon" label can mean different amounts depending on the country.

Quick reference:

• 1 liter = 0.264 US gallons
• 5 US gallons ≈ 18.93 liters
• 1 imperial gallon ≈ 1.201 US gallons

When a recipe, fuel figure, or product is from the United States, use 3.785 liters. When it's from the UK or older British sources, use 4.546 liters.