MihsabaHow to use
A cone frustum is the portion of a cone between two parallel circular bases. From radii R and r plus perpendicular height h, this calculator returns volume, slant height, lateral area, both base areas and total surface area.
- Enter the first base radius R.
- Enter the second radius r and perpendicular height h using the same length unit.
- Calculate the geometry outputs.
How it is calculated
Example
Example: R=5, r=3, h=8 gives ℓ=√68≈8.246 and V=π×8×(25+15+9)/3≈410.50 cubic units.
Important notes
Use the same length unit for all dimensions. Areas are squared units and volume is cubed units. If one radius is zero, the shape reduces to a cone; if the radii are equal, it reduces to a cylinder.
Frequently asked questions
Must R be larger than r?
No. The formulas are symmetric in the two radii, so either order works.
What is the difference between h and ℓ?
h is perpendicular height; ℓ is the slant distance along the side.
Does the calculator include both bases?
Yes. Total surface area includes lateral area plus both circular bases.
Is this calculator free?
Yes. It is free to use and requires no account.