How do I calculate volume?

For a box, multiply length by width by height; other shapes have their own formula.

What is the volume of a cylinder?

π times the radius squared times the height.

How many cubic centimetres in a litre?

1,000; a litre is a cube 10 cm on each side.

How to Calculate Volume

Published 9/10/2025 · 3 min read · Everyday calculators

Lena Hoffmann — Science & education writer at Allin

Mathematics · Physics

Checked against 2 sources

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In short

Volume is the space inside a 3D shape, measured in cubic units. For a box, multiply length × width × height. For a cylinder, multiply the circle's area (π × r²) by the height. A box 2 × 3 × 4 m holds 24 m³; a cylinder of radius 1 m and height 2 m holds π × 1² × 2 ≈ 6.3 m³. Keep every measurement in the same unit.

Volume is the space inside a shape. Here's how to find it for boxes, cylinders and spheres, and why keeping your units consistent is the whole game.

What volume is

Volume measures how much space a three-dimensional object takes up, or how much it can hold. Because space has three directions — length, width and height — volume is always measured in cubic units: cubic metres, cubic centimetres, and so on. If area (a flat measure) is length times width, volume adds the third dimension, which is why every volume formula ends up multiplying three lengths together in one form or another.

Boxes and cuboids

The everyday case is the box, or cuboid: length times width times height. A carton 2 m long, 3 m wide and 4 m tall holds 2 × 3 × 4 = 24 cubic metres. The order doesn't matter — multiplication is the same whichever side you start from. This one formula covers rooms, containers, tanks and packages, so it's the workhorse of volume; the rounder shapes are just variations that swap the flat base for a circle.

Cylinders and other round shapes

For anything with a constant cross-section, volume is the area of that cross-section times its length or height. A cylinder is a circle extended upward, so its volume is the circle's area (π × r²) times the height: a can of radius 1 m and height 2 m holds π × 1² × 2 ≈ 6.3 m³. A sphere follows (4/3) × π × r³, and a cone is exactly a third of the cylinder that would enclose it. Learn the base area and the pattern repeats.

Watch your units

The most common mistake isn't the formula, it's the units. Every measurement must be in the same unit before you multiply, and the answer comes out cubed. Converting is where people slip: one cubic metre is not 100 but 1,000,000 cubic centimetres, because each of the three sides is multiplied by 100. In everyday terms, one litre equals 1,000 cubic centimetres — a cube 10 cm on each side — which is the bridge between geometry and the capacity on a bottle.

Worked with our own calculator

Volume calculator

Given

Shape: Box
Length / side / radius: 5
Width / height: 3
Height (box only): 4

Result

Volume: 60

These figures are produced by the calculator below, not typed in by hand — they are recomputed whenever the tool changes.

Run it on your own figures →

Frequently asked questions

How do I calculate volume?: For a box, multiply length by width by height; other shapes have their own formula.
What is the volume of a cylinder?: π times the radius squared times the height.
How many cubic centimetres in a litre?: 1,000; a litre is a cube 10 cm on each side.

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Sources

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