Convert between litres, gallons, millilitres, cups and more.
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How do you convert litres to gallons and other volume units?
Each volume is converted to litres, then to the target unit; for example, 1 US gallon = 3.785412 L and 1 UK gallon = 4.54609 L. So 1 US gallon = 3.7854 litres = 3,785.4 millilitres = 16 US cups. US and UK gallons differ: a UK gallon is about 20% larger.
Understanding your result
US and UK (imperial) gallons differ: a UK gallon is about 20% larger. The cup, tablespoon and teaspoon here are US customary measures.
Formula and method
Each volume is converted to litres, then to the target unit. For example, 1 US gallon = 3.785412 L and 1 UK gallon = 4.54609 L.
Worked example
1 US gallon = 3.7854 litres = 3,785.4 millilitres = 16 US cups.
How to use this tool
- Enter the volume value.
- Choose the units to convert from and to.
- Read the result and the full unit table.
Common mistakes to avoid
- Mixing US and UK gallons — they are not the same size.
About the Volume Converter
Convert a volume between metric and US units, including cooking measures like cups and tablespoons. Enter a value and see every unit at once.
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Frequently asked questions
How many litres in a US gallon?
One US gallon is about 3.7854 litres.
Is a US gallon the same as a UK gallon?
No. A UK (imperial) gallon is about 4.546 litres, larger than the US gallon.