Online Tool Store
Surface Area Calculator
Calculate total surface area for cubes, rectangular prisms, spheres, cylinders, and cones with dimensions, formulas, and result breakdowns.
This works right here on your device — nothing gets sent out.
Calculate a solid's surface area
Select a shape and enter its dimensions.
Example shown: a cylinder with radius 5 cm and height 12 cm.
Total surface area
CylinderFormula
2πr(r + h)
Curved / side area
376.99 cm²
Bases / faces
157.08 cm²
How the Surface Area Calculator works
- Choose a solid — cube, rectangular prism, sphere, cylinder, or cone.
- Enter its dimensions (radius, height, side length, or length/width/height, depending on the shape) in any unit.
- Read the total surface area instantly, split into curved/side area and base area, with the formula used shown alongside.
The formulas
Each shape uses its own standard surface-area formula:
Cube: 6s² Rectangular prism: 2(lw + lh + wh) Sphere: 4πr² Cylinder: 2πr(r + h) Cone: πr(r + l), where l is the slant height
Example: a cylinder with radius 5 cm and height 12 cm gives 2π(5)(5 + 12) = 534.07 cm², split into 376.99 cm² of curved side area and 157.08 cm² across the two circular bases.
FAQ
Which shapes are supported?
Cube, rectangular prism, sphere, cylinder, and cone — each with its own inputs and formula, selected from the shape dropdown.
Does it break down the result by part of the shape?
Yes — alongside the total, it shows the curved or side area separately from the base/face area, so you can see how each part contributes.
What happens if I enter a negative or zero dimension?
It's rejected — all dimensions must be positive, since a solid can't have a zero or negative side, radius, or height.
Is my data uploaded anywhere?
No. The calculation runs entirely in your browser — nothing is sent to a server.
How we compare
| Feature | Online Tool Store | Single-shape calculator | Doing it by hand |
|---|---|---|---|
| Five shapes in one tool | ✓ | ✗ | Need to remember each formula |
| Side/base area breakdown | ✓ | Varies | Manual |
| No install | ✓ | ✓ | ✓ |
Switching between shapes without hunting for a different formula each time is what this tool is built for.