Volume Converter

Convert litres, ml, cubic metres, US and imperial gallons, cups, tablespoons and teaspoons.

Volume Converter

Worked example result

Converted volume	3.785412
Summary	1 US gal = 3.785412 L

One US gallon is exactly 3.785411784 litres — so a 12-gallon fuel tank holds about 45.4 litres.

Convert liquid and dry volumes through the millilitre. The US gallon is defined as exactly 231 cubic inches = 3.785411784 litres; its subdivisions follow: a US quart is a quarter gallon, a pint an eighth, a cup is 236.5882365 ml, a tablespoon 14.7867648 ml and a teaspoon 4.92892159 ml.

The imperial gallon used in the UK and Canada is bigger — exactly 4.54609 litres, about 20% more than a US gallon — which is why the same car gets better 'mpg' figures in Britain.

The formula

Result = Value × (factor of from-unit in ml) ÷ (factor of to-unit in ml)

Worked example

One US gallon is exactly 3.785411784 litres — so a 12-gallon fuel tank holds about 45.4 litres.

The example is pre-loaded in the result panel — press Calculate with your own numbers to replace it.

Frequently asked questions

How many cups are in a US gallon?

16 cups: a gallon is 4 quarts, each quart is 2 pints and each pint is 2 cups.

How many millilitres are in a litre?

Exactly 1000 ml, and one litre of water weighs almost exactly 1 kg — the metric system was designed that way.

Why are US and imperial gallons different?

The imperial gallon was redefined in 1824 based on 10 lb of water, while the US kept the older 231-cubic-inch wine gallon. The imperial gallon is about 20% larger.

Category: Unit Conversions calculators

Volume Converter