Liters to Gallons

1 US gallon = 3.785 litres. A UK (imperial) gallon is larger at 4.546 litres. Always verify which type is meant — they differ by about 20%.

The US gallon derives from the wine gallon used in colonial times; the UK gallon was standardised in 1824 as 10 pounds of water. The US retained the older standard.

A US half-gallon = 1.893 litres (common milk jug size). A UK half-gallon = 2.273 litres.