Cone Calculator
Volume and surface area of a cone from radius and height.
Worth Knowing
A cone holds exactly one-third the volume of a cylinder with the same base and height — a relationship the ancient Greeks proved and that still surprises people pouring liquid between the two shapes. Its surface area uses the slant height, the distance along the sloping side, which is longer than the vertical height and found via the Pythagorean theorem. This distinction between vertical and slant height is the most common source of error in cone calculations.
How to Use
- Enter Radius into the first field of the Cone Calculator.
- Fill in the rest: Height.
- Your result appears instantly as you type — there's no submit button or page reload.