Volume calculator
Volume of a cube, box, cylinder, sphere, cone or pyramid.
About this calculator
This volume calculator works out the volume of common 3D shapes, from a simple box to a cylinder, sphere or cone. Pick the shape and unit, then enter its measurements.
You also get the surface area, and the volume in litres, US and UK gallons, cubic metres and cubic feet, which helps when filling tanks, pots or containers.
How it works
Each shape has its own formula, shown with the result. Volume comes out in your unit cubed, and is also converted to litres and gallons.
Last reviewed:
Worked example
- Shape: Box (rectangular prism)
- Unit: Centimetres
- Length: 30
- Width: 20
- Height: 15
Volume: 9,000 cm³
Common questions
How do I calculate the volume of a cylinder?
Multiply pi by the radius squared, then by the height: V = π × r² × h. For a tank 30 cm across and 50 cm tall, the radius is 15 cm.
How many litres are in a cubic metre?
1,000. A litre is the volume of a cube 10 cm on each side.
What is the difference between volume and capacity?
Volume is the space a shape takes up. Capacity is how much a container holds, so the inside measurements matter. Measure inside the walls for capacity.
The story behind it
Where the idea came from: Archimedes showed that a sphere has two-thirds the volume of the smallest cylinder that contains it.
Archimedes was so proud of the sphere and cylinder result that he asked for it to be carved on his tomb. Greek mathematicians worked out the volumes of cones and pyramids too, by slicing them into ever-thinner layers. Those methods led, much later, to calculus, and their formulas are the ones used here.
Why you can trust this calculator
- It runs in your browser. Nothing you type into it is sent anywhere.
- The method is explained on this page, so you can check it yourself.
- Free to use, with no sign-up.
- Results are estimates, so please double-check anything important.
- Spotted a mistake? Tell us and we'll look into it.
After 15 years as a mathematics educator, I built CalculStore to give students, teachers, professionals and anyone working with numbers simple, reliable tools.
Meet the founder