Cone Calculator

A cone holds one-third of the cylinder with the same base and height. Its curved surface uses the slant height, found with Pythagoras.

Results update as you type.

Volume

301.5928947

Slant height (l)
10
Curved surface area (CSA)
188.4955592
Total surface area (TSA)
301.5928947

About this calculator

Enter the radius and height.

How to use it

  1. Enter the radius.
  2. Enter the height.
  3. Read the results.

The formula

l = √(r² + h²); V = ⅓πr²h; CSA = πrl; TSA = πr(r + l)
l
slant height

Worked example

Radius 6, height 8

  1. Slant height = 10.
  2. Volume ≈ 301.59; CSA ≈ 188.50; TSA ≈ 301.59.

What the result means

A conical tent needs canvas equal to its CSA.

Assumptions

  • All lengths in the same unit.

Limitations

  • Results are rounded to 10 significant figures.

Frequently asked questions

What is the volume of a cone?

⅓πr²h.

How do I find slant height?

√(r² + h²).

What is the CSA of a cone?

πrl.

Last reviewed on 3 October 2026. Found a mistake? Tell us.