1 US gallon in litres
A US fuel volume needs a metric value.
- 1 US gallon = 3.785411784 L
- Result: 3.785411784 L
A US gallon is 3.785411784 litres. A UK gallon is larger: 4.54609 litres.
Volume Converter
This converter handles metric volume and the US and UK cooking units. The two systems are labelled separately, because a US gallon and a UK gallon differ by about 20%.
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Result
0.264172 gal
Enter a value to convert The converted result appears here as you type.
Other common conversions +
How to use this tool
- 1 Enter the volume and choose the source unit.
- 2 Pick the target unit; metric, US and UK units appear in separate groups.
- 3 Use swap to reverse the direction, and set the decimal places you need.
- 4 Other common conversions are listed below the result and can be copied.
Formula and calculation logic
Converting to litres
L = Value × Factor
One US gallon is exactly 3.785411784 L, one US cup is 0.2365882365 L and one UK pint is 0.56826125 L.
Converting from litres
Result = L ÷ Target factor
For 1 litre in US cups: 1 ÷ 0.2365882365 = 4.226752838 cups. The conversion is exact until display rounding.
Worked example
1 cup in millilitres
A US recipe lists one cup of liquid.
- 1 US cup = 0.2365882365 L
- 0.2365882365 × 1000 = 236.5882365
- Result: 236.5882365 mL
One US cup is about 236.59 mL. A metric cup of 250 mL is a different unit.
Edge cases and accuracy
US and UK units differ
A US gallon is 3.785411784 L while a UK gallon is 4.54609 L. Pints, quarts and gallons are therefore not interchangeable between the two systems.
Cooking units vary
The converter uses US customary cooking units. A metric cup (250 mL) and an Australian tablespoon (20 mL) are not the same as the US values.
Negative volumes
Volume cannot be negative. The converter rejects negative input rather than returning an impossible value.
Frequently asked questions
How many litres are in a US gallon? + −
One US gallon is exactly 3.785411784 litres. A UK gallon is 4.54609 litres.
How many millilitres are in a US cup? + −
One US cup is 236.5882365 mL. A metric cup is 250 mL, so recipes from different countries can differ by about 5%.
Why are US and UK units separate? + −
They are based on different historical standards. Mixing them up changes the result by about 20% for gallons.
Can I convert between volume and weight? + −
No. A litre of water and a litre of flour have different masses. Without a density for the specific ingredient, volume-to-weight conversion would be a guess.
Does the converter support cubic metres? + −
Yes. One cubic metre is exactly 1000 litres.