What do I need to enter?

Bottom radius (R), Top radius (r), Height, Units. Optional fields can be left blank.

Frustum Calculator

Find the volume and surface area of a conical frustum — a cone with its top cut off, like a bucket or lampshade.

Volume

205.25072

Add the squared radii and their product
R^{to the power of 2} + Rr + r^{to the power of 2}
5^{to the power of 2} + 5 × 3 + 3^{to the power of 2} = 49
Volume
V = πh(R^{to the power of 2} + Rr + r^{to the power of 2}) ÷ 3
π × 4 × 49 ÷ 3 = 205.25072

V = 1⁄3 πh(R² + Rr + r²); slant s = √((R − r)² + h²); lateral area = π(R + r)s

How does the frustum calculator work?: V = 1⁄3 πh(R² + Rr + r²); slant s = √((R − r)² + h²); lateral area = π(R + r)s.
What do I need to enter?: Bottom radius (R), Top radius (r), Height, Units. Optional fields can be left blank.