Surface Area Calculator
Calculate the surface area of a cube, rectangular prism, cylinder, sphere, cone, or square pyramid with steps.
Calculate surface area
Answer
Surface area = 96
How to use the surface area calculator
Choose a solid and enter its dimensions to get the total surface area; cones and pyramids first derive the slant height with the Pythagorean theorem.
- Choose a solid shape.
- Enter the required dimensions.
- For a cone or pyramid, find the slant height l with the Pythagorean theorem.
- Substitute into the surface-area formula and read the result.
Formula or method
Cube S = 6s^2; prism S = 2(lw + lh + wh); cylinder S = 2 pi r (r + h); sphere S = 4 pi r^2; cone S = pi r^2 + pi r l; pyramid S = a^2 + 2 a l.
Worked examples
Cylinder surface area
Problem: r = 3, h = 4
Solution: S = 2 * pi * 3 * (3 + 4) = 42pi ≈ 131.95.
Cone surface area
Problem: r = 3, h = 4
Solution: l = sqrt(3^2 + 4^2) = 5, so S = pi*3^2 + pi*3*5 = 24pi ≈ 75.40.