How to find the volume of a cube
The volume of a cube is its side length cubed: V = s³. For a side of 4, V = 4³ = 64 cubic units, and the surface area is 6 × 4² = 96 square units. For a six-sided box with unequal edges, multiply length × width × height instead.
The formula is really that box rule in disguise. Volume is length × width × height, and in a cube all three edges are equal, so the product collapses to s × s × s. Once the three edges stop being equal you need the rectangular prism volume calculator instead.
How to use this calculator
Enter the side length — every edge of a cube is equal. The volume appears in cubic units and the surface area in square units. For a round solid, try the sphere volume calculator.
Whatever unit you type in comes back cubed, so a side in centimetres gives cm³. Remember that a unit conversion applies three times over in a volume: 1 m³ is 100³ = 1,000,000 cm³, not 100 cm³.
Worked example
A storage cube measures 4 ft on each edge. Volume = 4³ = 64 cubic feet. To wrap all six faces you'd cover 6 × 16 = 96 square feet. Compare a flat face with the rectangle area calculator.
Volume grows fast with size. Doubling the edge from 4 ft to 8 ft gives 8³ = 512 cubic feet — eight times the capacity, while the surface area only quadruples, which is why larger containers are more material-efficient.
Frequently asked questions
- What is the formula for the volume of a cube?
- V = s³, where s is the side length. Multiply the side by itself three times.
- What is the volume of a cube with side 4?
- 64 cubic units (4 × 4 × 4).
- How do I find the surface area of a cube?
- Surface area = 6 × s². For side 4 that is 6 × 16 = 96 square units, shown in the badge.
- What units is the volume in?
- Cubic units of whatever you measured the side in — cubic inches, cm³, m³, etc.
- How do I find the side length if I know the volume?
- Take the cube root of the volume. A volume of 64 cubic units gives a side of ∛64 = 4. This is the standard way to size a cubic tank or box when only its capacity is specified.