Value, From, To
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How this calculator works
US liquid measures are all fractions of the US gallon, which is defined as 231 cubic inches or exactly 3.785411784 liters. The imperial gallon used in the United Kingdom is about 20% larger, so recipes and fuel figures from the two systems are not interchangeable.
Formula
- 1 US gallon = 3.785411784 L (exact) = 4 quarts = 8 pints = 16 cups = 128 fl oz
- 1 US cup = 16 tablespoons = 48 teaspoons
- 1 imperial gallon = 4.54609 L (exact)
- 1 m³ = 1,000 L
Worked example
1 gal to l
- Value
- 1
- From
- US gallon (gal)
- To
- Liter (L)
Result3.7854118 L
1 gal = 3.7854118 L. 1 gal = 3.7854118 L.
Things to keep in mind
- US nutrition labels use a rounded 240 mL cup, and metric recipes often use a 250 mL cup. This converter uses the US customary cup of 236.59 mL.
Frequently asked questions
How many liters are in a gallon?
A US gallon is 3.785 liters. An imperial (UK) gallon is 4.546 liters.
How many milliliters are in a cup?
A US customary cup is 236.59 mL. Metric recipes commonly use 250 mL, and US food labels use 240 mL.
How many tablespoons are in a cup?
16 US tablespoons, or 48 teaspoons.
Sources
More unit converters calculators
Results are estimates based on the values you enter and the published method shown above. They do not replace professional medical, financial or legal advice. Method reviewed October 7, 2026. About this site