Gallon Converter
Convert US and UK gallons to liters, quarts, pints, cups, fluid ounces, cubic inches, and cubic feet instantly. Free online volume unit converter with comparison chart.
About This Calculator
The Gallon Converter is a free online volume unit conversion tool that instantly converts US gallons and UK (Imperial) gallons to liters, quarts, pints, cups, fluid ounces, cubic inches, cubic feet, and milliliters. Whether you are cooking, brewing, fueling your vehicle, or working on a construction project, this converter handles both US customary and Imperial measurement systems with precision.
One US gallon equals 3.78541 liters, while one UK gallon equals 4.54609 liters — about 20% larger. The US gallon originated from the English wine gallon used before 1824, while the UK Imperial gallon was defined in 1824 as the volume of 10 pounds of distilled water at 62°F. Both systems share the same number of quarts (4), pints (8), and cups (16) per gallon, but each unit has a different actual volume between the two systems. For example, a US pint is 473 mL while a UK pint is 568 mL, so ordering a pint in the UK gets you about 20% more liquid.
Regional notes: In the United States, gallons are commonly used for fuel economy (miles per gallon), milk, and other beverages. In the United Kingdom, Imperial gallons are used for fuel consumption (miles per gallon) and beer/cider sales. In India and most other countries, the metric system uses liters as the standard volume unit, but gallons still appear in imports, industrial applications, and legacy contexts.
Frequently Asked Questions
How many liters are in a US gallon?
One US gallon equals exactly 3.78541 liters. This is the standard gallon used in the United States for measuring fuel, milk, and other liquids.
How many liters are in a UK gallon?
One UK gallon (Imperial gallon) equals exactly 4.54609 liters. The UK gallon is about 20% larger than the US gallon and is used in the United Kingdom and some Commonwealth countries.
How many quarts are in a gallon?
There are 4 quarts in both a US gallon and a UK gallon. However, the US quart is 0.946 liters while the UK quart is 1.136 liters, reflecting the different gallon sizes.
How many pints are in a gallon?
There are 8 pints in both US and UK gallons. A US pint is 473 mL while a UK pint is 568 mL. When ordering a pint in the UK, you get about 20% more volume than a US pint.
How many cups are in a gallon?
There are 16 US cups in a US gallon and 16 UK cups in a UK gallon. A US cup is 236.6 mL while a UK cup is 284 mL.
How many fluid ounces are in a gallon?
There are 128 US fluid ounces in a US gallon and 160 UK fluid ounces in a UK gallon. A US fluid ounce is 29.57 mL while a UK fluid ounce is 28.41 mL.
Is this gallon converter free to use?
Yes, this gallon converter is completely free to use with no registration or limits. Convert between US gallons, UK gallons, liters, quarts, pints, cups, and fluid ounces instantly.
What is the difference between US and UK gallons?
A US gallon is 3.785 liters while a UK (Imperial) gallon is 4.546 liters. The UK gallon is 20% larger. The US gallon is based on the wine gallon used in England before 1824, while the UK gallon was redefined in 1824 as the volume of 10 pounds of water.