Gallon Converter
Convert gallons to liters, quarts, pints, cups, and fluid ounces in both US and imperial units. The hub for every gallon conversion: gallon to liter, gallon to litre, gallons to litres, gallons to ounces, gallons to quarts, gallons to pints, gallons to cups, and more.
Gallon conversion calculator
Gallon definitions
US liquid gallon
1 US gallon = 3.785411784 liters (commonly written 3.78541178 L) = 231 cubic inches, exactly. Subdivisions: 4 quarts = 8 pints = 16 cups = 128 fluid ounces.
Imperial gallon
1 imperial gallon = 4.54609 liters, exactly. Subdivisions: 4 quarts = 8 pints = 160 fluid ounces. Used in the UK, Canada, and some Caribbean countries.
US gallon vs imperial gallon
| Unit | US | Imperial |
|---|---|---|
| 1 gallon in liters | 3.78541178 | 4.54609 |
| 1 gallon in milliliters | 3785.41 | 4546.09 |
| 1 gallon in cubic inches | 231 | 277.42 |
| Fluid ounces per gallon | 128 | 160 |
| 1 fluid ounce in mL | 29.5735 | 28.4131 |
| 1 quart in mL | 946.35 | 1136.52 |
The imperial gallon is 1.2009 times the US gallon, about 20.09 percent larger. So 1 imperial gallon of water weighs more than 1 US gallon of water.
Quick gallon to liters table
| Gallons | US gallons to liters | Imperial gallons to liters |
|---|---|---|
| 1/2 gallon | 1.89270589 | 2.273045 |
| 1 gallon | 3.78541178 | 4.54609 |
| 2 gallons | 7.57 | 9.09218 |
| 5 gallons | 18.9270589 | 22.73 |
| 10 gallons | 37.85411784 | 45.4609 |
| 20 gallons | 75.71 | 90.9218 |
| 55 gallon drum | 208.20 | 250.03 |
Everyday examples: a 5 gallon water jug holds 18.93 liters, a 12 gallon car fuel tank holds 45.42 liters, and a 15 gallon tank holds 56.78 liters.
Pint, quart, gallon chart
US customary volume units build up from the fluid ounce: 1 US pint = 16 fluid ounces, 1 US quart = 2 pints = 32 fluid ounces, and 1 US gallon = 4 quarts = 128 fluid ounces. Wondering how many ounces are in a gallon? In US measure that means 128 fluid ounces. For gallon to fluid ounces just multiply by 128; gallons to pints and gallons to cups scale from the same base (8 pints or 16 cups per US gallon). In the imperial system the pint is larger (20 imperial fluid ounces), so 1 imperial pint = 568.26 mL versus 473.18 mL for a US pint, but both systems keep 8 pints per gallon.
Gallon history in brief
The US gallon descends from the Queen Anne wine gallon of 1707, defined as 231 cubic inches. The imperial gallon was defined in 1824 as the volume of 10 pounds of water at 62 F, later fixed at exactly 4.54609 liters by the UK Weights and Measures Act of 1985. Canada metricated in the 1970s but the imperial gallon still appears in older specifications there.
Frequently asked questions
How many liters are in a gallon?
How many liters are in 5 gallons?
How many fluid ounces are in a gallon?
What is the difference between a US gallon and an imperial gallon?
How many quarts are in a gallon?
How many pints are in a gallon?
How many cups are in a gallon?
How many milliliters are in a gallon?
How many cubic inches are in a gallon?
How many gallons are in a liter?
How much does a gallon of water weigh?
How many liters are in a 55 gallon drum?
How many liters are in half a gallon?
How many liters are in 10 gallons?
Why are there two different gallon sizes?
How many cubic feet are in a gallon?
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