Formula
value in target unit = value × (m³ per source unit) ÷ (m³ per target unit)
- 1 US gallon = 231 in³ = 3.785411784 L
- 1 imperial gallon = 4.54609 L
- 1 L = 0.001 m³
Convert to cubic metres, then to the unit you want.
Worked example
1 US gallon in litres
- Value
- 1
- From
- US gallon (US gal)
- To
- Litre (L)
US gallon to Litre
3.785411784 L
In words: 1 US gal = 3.785411784 L
How it works
The same word means different amounts on either side of the Atlantic. A US gallon is 3.785 litres (231 cubic inches); an imperial gallon, still used for UK fuel economy, is 4.546 litres — about 20% larger. The pint, quart and fluid ounce inherit the difference, so both versions are listed by name.
Cooking units follow the US customary system: a US cup is 236.588 mL, a tablespoon a sixteenth of a cup. Nutrition labels in the US use a rounded 240 mL “cup”, and metric countries often use 250 mL, so recipes can differ a little. For the fuel-economy side of gallons see Fuel Economy Converter; for mass use Weight Converter.
Assumptions and limits
- US legal and metric cooking cups aren't listed separately.
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