How many liters in a gallon?

Gallon to Liter Conversion

1 us liquid gallon = 3785.412 millilitres
1 Gallon [Dry, US] = 4.4048838 Liters
1 Gallon [UK] = 4.54609 Liters

A gallon is a unit of measurement for liquid capacity in both the US customary units and the British imperial systems of measurement. Three significantly different sizes are in current use: the imperial gallon defined as 4.54609 litres, which is used in the United Kingdom, Canada, and some Caribbean nations; the US gallon defined as 231 cubic inches (3.785 L), which is used in the US and some Latin American and Caribbean countries; and the least-used US dry gallon defined as 1⁄8 US bushel (4.405 L).
While there is no official symbol for the gallon (as there are for SI units), gal is in common use.