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 tool runs entirely in your browser. Your files are never uploaded to a server.
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.