About the Volume Calculator
Work out the volume of a cube, box, cylinder, sphere, hemisphere, cone, pyramid, triangular prism or ellipsoid, and see it in litres, millilitres, US and UK gallons, cubic metres, cubic feet and more.
Type the measurements and the answer updates as you go, with the formula shown underneath.
How it works
Each shape uses its standard formula, worked out to 40 significant digits so rounding only happens in what you see. The volume is shown in the cube of the unit you measured in, then converted.
Conversions use the exact definitions: a litre is 1,000 cm³, a US gallon is 231 cubic inches (3.785411784 L) and a UK gallon is 4.54609 L, so tank and container sizes come out right.
Box V = l × w × h Cylinder V = π × r² × h Sphere V = 4/3 × π × r³ Cone V = 1/3 × π × r² × h Pyramid V = 1/3 × l × w × h
Assumptions and limits
- All lengths are in the same unit. Use the radius (half the diameter) for round shapes.
- For a container, measure the inside to get how much it holds.
- Use a dot for decimals (12.5), not a comma.
Worked examples
A water tank
A cylindrical tank with a radius of 50 cm and a height of 120 cm holds π × 50² × 120 = 942,477.8 cm³, which is 942.48 litres or 248.98 US gallons.
Concrete for a slab
A slab 4 m × 3 m × 0.1 m is 1.2 m³ of concrete, about 1.57 cubic yards.
A football
A size-5 ball has a radius of about 11 cm: 4/3 × π × 11³ = 5,575.28 cm³, about 5.6 litres of air.
How to use the Volume Calculator
- Choose the shape. Box, cylinder, sphere, cone and more.
- Enter the measurements. In mm, cm, m, inches, feet or yards.
- Read the volume. In litres, gallons and cubic units.
Frequently asked questions
How many litres are in a cubic metre?
Exactly 1,000 litres, because a litre is defined as one cubic decimetre (10 cm × 10 cm × 10 cm). Enter your sizes in metres or centimetres to see litres directly in the table.
Are US and UK gallons the same?
No. A US gallon is 3.785411784 litres and a UK (imperial) gallon is 4.54609 litres, about 20% bigger. Both are shown, so check which one your country or product uses.
How do I measure a cylinder?
Measure straight across the circular end and halve it to get the radius, then measure the height. For how much a container holds, measure the inside, not the outside.
How accurate are the results?
Every volume is calculated with 40-digit precision and the official definitions of litres and gallons. The answer is only rounded at the end, to the number of decimal places you pick in the menu.
How do I find the volume of an odd shape?
Split it into shapes this tool knows, such as a box plus a half cylinder, work out each part and add them. For an irregular object, measuring the water it pushes out is often easier.
This tool runs entirely in your browser. What you enter or upload stays on your device and is never sent to our servers.