Volume Calculator
Calculate the volume of a cube, box, sphere, cylinder, cone or pyramid from its dimensions, with the exact formula shown for each shape.
About the Volume Calculator
This volume calculator covers the six shapes that appear in almost every geometry problem and real-world estimate: cube, rectangular box, sphere, cylinder, cone and square pyramid. Pick a shape, enter its dimensions, and the volume appears instantly along with the formula used, so you can follow the working or reuse it by hand.
The formulas are the classical ones: a³ for a cube, l×w×h for a box, (4/3)πr³ for a sphere, πr²h for a cylinder, and one third of the corresponding prism for the cone ((1/3)πr²h) and pyramid ((1/3)a²h) — that factor of one third is the signature of any shape that tapers to a point.
Units are up to you: enter centimetres and the answer is in cm³, metres gives m³, inches gives in³. Just keep every dimension in the same unit. Useful for homework, tank and container sizing, soil and concrete estimates, and shipping volumes.
How to Use the Volume Calculator
- 1Choose the shape from the dropdown.
- 2Enter its dimensions — all in the same unit.
- 3Read the volume in that unit cubed, with the formula displayed beside it.
- 4Switch shapes to compare capacities.
Frequently Asked Questions
How do I calculate the volume of a cylinder? A worked example
V = π × r² × h. A tank with radius 0.5 m and height 1.2 m holds π × 0.25 × 1.2 ≈ 0.9425 m³. Since 1 m³ = 1,000 litres, that's about 942 litres.
Why do the cone and pyramid formulas have a 1/3?
A cone is exactly one third of the cylinder with the same base and height, and a pyramid is one third of its matching prism — a result proved by calculus (or by cleverly slicing solids, as the ancient Greeks did). So a cone with r = 3 and h = 10 has V = (1/3)π × 9 × 10 ≈ 94.25 cubic units, versus 282.74 for the full cylinder.
What units does the calculator use?
Whatever you put in. Volume is always length cubed, so entering dimensions in cm returns cm³, metres returns m³, feet returns ft³. To convert afterwards: 1 m³ = 1,000 L = 35.31 ft³, and 1 ft³ ≈ 28.32 L.
How do I find the volume of a sphere from its diameter?
Halve the diameter to get the radius first. A ball 20 cm across has r = 10 cm, so V = (4/3)π × 1000 ≈ 4,188.8 cm³ ≈ 4.19 litres. Using the diameter directly in the formula is the most common mistake — it inflates the answer 8-fold.
Can I use this for irregular shapes?
Break the object into these primitives and add the volumes: a grain silo is a cylinder plus a cone on top; a capsule is a cylinder plus two half-spheres (one full sphere). For truly irregular objects, water displacement is the practical method.