What this calculator does
A cube's volume comes from a single measurement: the side length, cubed. Because all six faces of a cube are identical squares and all twelve edges are the same length, one number is enough to describe the whole shape, unlike a general rectangular box which needs three separate dimensions.
Volume of a cube is one of the first three-dimensional formulas most people learn, and it stays useful well beyond the classroom: storage cubes, dice, ice cubes, shipping cartons and modular furniture are all close enough to a true cube that side³ gives a good working answer.
The formula
Raise the side length to the third power: V = a³. The calculator also returns the surface area (six identical square faces, 6a²) and the space diagonal, the straight-line distance from one corner of the cube through its interior to the opposite corner (a√3).
| Term | Meaning |
|---|---|
| a | The side length of the cube, the same for all twelve edges. |
| Volume | The space enclosed by the cube: a³. |
| Surface area | The total area of all six square faces: 6a². |
| Space diagonal | The distance from one corner to the opposite corner through the inside of the cube: a√3. |
The inputs explained
| Field | What to enter |
|---|---|
| Side length | The length of one edge of the cube. Every edge is the same length by definition. |
When to use it
Working out storage or shipping capacity
A cube-shaped box or storage cube's volume tells you how much it holds, and dividing by 1,000 converts a result measured in centimetres straight into litres.
Comparing cube sizes at a glance
Because volume scales with the cube of the side length, a cube twice as wide holds eight times as much, not twice as much, which is worth checking before assuming a "double size" box doubles capacity.
Finding material for a cube-shaped structure
Surface area gives the material needed to cover or build all six faces, useful for anything from a cardboard box to a cube-shaped planter.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How volume and surface area scale with side length
Volume and surface area for a range of side lengths, showing how differently the two figures scale.
| Side length | Volume | Surface area |
|---|---|---|
| 2 | 8.000 | 24.000 |
| 4 | 64.000 | 96.000 |
| 6 | 216.000 | 216.000 |
| 8 | 512.000 | 384.000 |
| 10 | 1,000.00 | 600.000 |
| 20 | 8,000.00 | 2,400.00 |
Questions
What is the formula for the volume of a cube?
V = a³, where a is the length of one edge. Since every edge of a cube is the same length, this single measurement is all that is needed.
How is the volume of a cube different from a rectangular box?
A rectangular box needs three separate measurements (length, width, height) multiplied together, because its three dimensions can differ. A cube is the special case where all three are equal, which is why one measurement cubed is enough.
How do I convert a cube's volume to litres?
If the side length is measured in centimetres, divide the volume in cubic centimetres by 1,000 to get litres, since 1 litre equals 1,000 cm³. This calculator shows that conversion automatically.
Why does volume grow so much faster than surface area as a cube gets bigger?
Volume scales with the cube of the side length (a³) while surface area scales with its square (a²). As the side length grows, the cubic term outpaces the squared term, so larger cubes hold proportionally far more than their surface area alone would suggest.
For a box with three different dimensions, or other common solids, see the volume of common shapes calculator. For a cylindrical container instead, use the volume of a cylinder calculator.