A single calculator covering the surface area of five common 3D shapes — cube, sphere, cylinder, rectangular prism, and cone.
How it works
Each shape uses its own standard geometric formula, summing the area of every face (or the curved surface, for round shapes).
What this does not include
This does not include volume — for the space a shape encloses rather than its outer surface, use this site’s volume calculator instead.
How to use this calculator
- Select a shape, then enter its dimensions.
A worked example
A cube with side 4: surface area = 6 × side² = 96.
A sphere with radius 3: surface area = 4πr² = 113.0973.
What the variables mean
| Variable | Meaning |
|---|---|
| Shape | Which solid is being measured — cube, sphere, cylinder, and more |
| Dimensions | Only the fields relevant to the selected shape are used |
Edge cases worth knowing
Each shape uses a completely different formula — a cube’s six flat faces and a sphere’s single curved surface have nothing in common mathematically, which is why this calculator switches formulas based on the selected shape rather than using one universal equation.
Only the fields relevant to the chosen shape matter — entering a radius while “cube” is selected has no effect, since the cube calculation only reads the side length.
Frequently asked questions
What’s the difference between surface area and volume?
Surface area measures the total area of a shape’s outer faces (useful for paint or wrapping material); volume measures the space it encloses (useful for capacity).
Why does the cylinder formula include both the radius and height?
It accounts for both circular end caps (2πr²) and the curved side wrapped around the height (2πrh), combined into one formula.
What’s a slant height, for the cone?
The distance from the cone’s tip down along its curved surface to the edge of its base — different from the cone’s straight vertical height.
