Volume Converter

How the converter works

Every unit is stored as an exact number of cubic metres, and a conversion multiplies by the source size and divides by the target size. The US customary units all descend from the US gallon, defined as exactly 231 cubic inches; since an inch is exactly 2.54 cm, the gallon is exactly 3.785411784 litres. The UK imperial gallon is defined directly as 4.54609 litres. Everything else follows by exact fractions.

Worked examples

Example 1: 2 US gallons in litres

2 × 3.785411784 = 7.570824 L.

Example 2: a 500 mL bottle in US fluid ounces

500 ÷ 29.5735295625 = 16.907011 US fl oz, just over a US pint's worth of 16 fl oz.

Example 3: a UK pint versus a US pint

568.26125 ÷ 473.176473 = 1.200950: a UK pint is about 20% larger than a US pint, which surprises many travellers ordering a beer.

Example 4: 3 tablespoons in millilitres

3 × 14.78676478125 = 44.360294 mL, roughly 45 mL in a metric kitchen.

How to read the result

The headline is the volume in your target unit, the formula line shows the single multiplier between the two units, and the table lists the same volume in all 16 units with the target highlighted. Up to six decimals are shown, which is far more precision than any kitchen jug or fuel pump offers; round to suit the job.

US, UK and metric cups and spoons

Cooking measures are where volume units cause the most confusion. A US customary cup is 236.59 mL, but US nutrition labels use a rounded "legal cup" of 240 mL, while Australia, New Zealand and Canada commonly use a 250 mL metric cup, and the UK mostly weighs ingredients instead. A metric tablespoon is 15 mL in most countries but 20 mL in Australia. For recipes the differences rarely matter for liquids, but they add up for baking. When a recipe's origin is unclear, weighing dry ingredients with the weight converter is more reliable than converting cups.

Common uses

Typical conversions include fuel economy and tank sizes between litres and gallons, drink and bottle sizes between millilitres and fluid ounces, recipe quantities between cups, spoons and millilitres, aquarium and pool volumes between gallons, litres and cubic metres, paint coverage, and engine displacement between cubic centimetres, litres and cubic inches — a 5.7-litre engine is about 348 cubic inches. For water at room temperature, 1 litre weighs almost exactly 1 kilogram, a handy cross-check between volume and mass.

Limits

This converter handles liquid and general volume. It does not include US dry pints and quarts, which are slightly larger than liquid ones and are used mainly for produce, or barrels, which vary by industry (an oil barrel is 42 US gallons). Converting a volume to a weight requires the substance's density and is not done here, except for the water rule of thumb above. For lengths and areas, see the length converter and the area converter.

Volume of common containers

To sense a converted figure, compare it with familiar containers. A standard can of soda is 12 US fl oz (355 mL) in the US and 330 mL in much of Europe. A wine bottle is 750 mL, about 25.4 US fl oz. A large milk jug in the US is one gallon (3.79 L), while in the UK milk is sold in multiples of the imperial pint. A typical bathtub holds around 150 to 300 litres, and a home swimming pool tens of cubic metres; one cubic metre is 1,000 litres or about 264 US gallons.

For a box-shaped tank or room, multiply length, width and height in the same unit to get the volume in that unit cubed, then convert: a tank 120 cm × 40 cm × 50 cm holds 240,000 cm³, which is 240 litres or about 63.4 US gallons. For a cylinder, multiply π by the radius squared and by the height.