Surface Area Calculator

Work out the total surface area of a cube, cuboid, cylinder, cone or sphere — exactly in terms of π, with each part shown.

Result

Enter values and press Calculate to see the result.

Formula

Acuboid=2(lw+lh+wh)A_{\text{cuboid}} = 2(lw + lh + wh)

Six rectangular faces, in three matching pairs.

Acylinder=2πr2+2πrhA_{\text{cylinder}} = 2\pi r^2 + 2\pi r h

Two circular ends plus the curved side.

Acone=πr2+πrl,l=r2+h2A_{\text{cone}} = \pi r^2 + \pi r l,\quad l = \sqrt{r^2 + h^2}

The base plus the curved surface, using the slant height l.

Asphere=4πr2A_{\text{sphere}} = 4\pi r^2

Four times the area of a circle with the same radius.

How to use this calculator

  1. Choose the shape and enter its measurements in the same unit.
  2. Press Calculate. Areas come out in that unit squared.

Worked example

A cylinder with radius 3 and height 5

The two circular ends: 2π × 3² = 18π.

The curved side: 2π × 3 × 5 = 30π.

Total surface area = 18π + 30π = 48π ≈ 150.796447.

Frequently asked questions

What is the difference between surface area and volume?

Surface area is the area of the outside (how much paint covers it); volume is the space inside (how much it holds).

What is the slant height of a cone?

The distance from the tip down the side to the edge of the base: l = √(r² + h²).