Surface Area Calculator

Choose a solid and enter lengths in one unit. The result is surface area in that unit squared — the wrapping, not the volume inside.

How it works

Surface area is the sum of the faces. A cube is 6s²; a box is 2(lw+lh+wh); a sphere is 4πr²; a closed cylinder is 2πrh + 2πr² (lateral plus two bases).

A cone uses slant height ℓ = √(r²+h²), then πrℓ + πr². Volume of the same solid is a different quantity (unit³) on the volume page.

Formula

Cube: SA = 6s²
Box: SA = 2(lw + lh + wh)
Sphere: SA = 4πr²
Cylinder: SA = 2πrh + 2πr²
Cone: ℓ = √(r² + h²),  SA = πrℓ + πr²

Worked examples

A cube of side 2
cube, s = 2 → 24 unit²
A sphere of radius 2
r = 2 → 16π ≈ 50.265 unit²

Useful notes

Cylinder and cone include the base(s). Lateral area is shown as a detail where it differs.

FAQ

How do I find the surface area of a sphere?: SA = 4πr². Radius 2 gives 16π.
Does the cylinder include the lids?: Yes, the primary result is the closed cylinder. Lateral area (the tube only) is listed as a detail.
Is surface area the same as volume?: No. Surface area is a wrapping (unit²). Volume is the interior (unit³).

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