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Cone Calculator

Calculate the volume, surface area, and slant height of a cone from its radius and height.

Volume (cubic units)
37.7
Surface area (square units)
75.4
Slant height (units)
5
Diagram

How it works

  1. 1Enter the cone’s base radius and vertical height.
  2. 2Read the volume ((1/3)π r² h), surface area, and slant height.
  3. 3Slant height is √(r² + h²); surface area is π r (r + slant).

Use cases

  • Find the capacity of a conical container or hopper.
  • Estimate material for a cone, funnel, or party hat.
  • Check geometry homework on cones.

Frequently asked questions

What is the volume of a cone?

Volume = (1/3) × π × radius² × height — exactly one third of a cylinder with the same base and height. Radius 3, height 4 give about 37.70 cubic units.

What is slant height?

The distance from the base edge to the apex along the surface: slant = √(radius² + height²). For radius 3 and height 4 it is 5.

What is the total surface area?

The base plus the curved side: π r² + π r × slant = π r (r + slant). Radius 3, height 4 give about 75.40 square units.

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