Volume Converter

A volume converter that never mixes up US and UK measures

This volume converter handles liquid and solid volume in one place: millilitres and litres, cubic metres and cubic centimetres, US customary teaspoons, cups, pints, quarts and gallons, the separate Imperial (UK) fluid ounce, pint and gallon, cubic inches, feet and yards, and the 42-gallon oil barrel. Each unit is labelled “US” or “UK”, because a gallon, a pint and even a fluid ounce are different sizes on each side of the Atlantic.

Use it to size a water tank, compare a 2-litre bottle with a half-gallon carton, read a British recipe in American cups, work out how many cubic feet a fridge holds, or follow fuel prices quoted per barrel. Results update as you type and come with the exact factor used.

How to use the Volume Converter

1. Type the quantity in the Value box — 2, 0.75, 1/2 and 3e3 are all accepted.
2. Choose the starting unit in From. Search “gal”, “pint” or “UK” to narrow the list; US and Imperial units sit in separate groups.
3. Choose the unit you want in To, or tap the round swap button to reverse the conversion.
4. Read the result with its formula, change Precision if needed, and press Copy to use the number elsewhere.
5. Check the full list of volume units under the result, or tap one of the common conversions like “1 gal (US) → L”.

Volume Converter features

Exact volume conversion factors

The litre is one cubic decimetre, so 1 L = 1,000 cm³ and 1 m³ = 1,000 L. The US gallon comes from the old English wine gallon of 231 cubic inches; the imperial gallon was redefined in metric terms by the UK Weights and Measures Act 1985 as exactly 4.54609 litres.

US vs UK: the pint puzzle

An imperial pint holds 20 imperial fluid ounces, while a US pint holds 16 US fluid ounces. So a British pint (568 ml) is about 20% bigger than an American one (473 ml) — yet the British fluid ounce (28.41 ml) is about 4% smaller than the American one (29.57 ml). The bigger pint wins because it contains more ounces.

The same 1.2 ratio runs through quarts and gallons: one imperial gallon is 1.20095 US gallons. That is why UK fuel-economy figures in miles per gallon look higher than US figures for the same car — the fuel economy converter handles that properly.

Worked examples

Litres to US gallons — divide by 3.785411784. A 50-litre fuel tank holds 50 ÷ 3.785411784 = 13.21 US gallons, or 50 ÷ 4.54609 = 11.0 imperial gallons.

Millilitres to US fluid ounces — divide by 29.5735295625. A 500 ml water bottle is 16.91 US fl oz, and a 330 ml can is 11.16 US fl oz.

Cubic metres to litres — multiply by 1,000. A 1.5 m³ water tank holds 1,500 L; a 1,000-litre tank is 35.3 cubic feet.

Weighing ingredients rather than measuring them? The cooking converter converts cups to grams for flour, sugar, butter and more.

Common volume conversions

Tips for converting volume

• Check the origin of the recipe or label. A “pint” of milk in London is 568 ml; in New York it is 473 ml.
• Millilitres and cubic centimetres are the same. 1 ml = 1 cm³, which is why engine sizes in cc are effectively millilitres.
• Volume is not weight. A litre of water weighs about 1 kg, but a litre of oil or flour does not. Convert to weight only with a density.
• Cubic feet for appliances and moving. Fridges and trucks are often rated in ft³ in the US; multiply by 28.32 to get litres.
• Sand and aggregate in India. These are sold by the brass, a trade unit of 100 cubic feet (2.832 m³); the brass calculator works out cft, brass and m³ for a load.