Formula and example
How it is calculated
V=πh(R²+Rr+r²)/3; s=√[h²+(R−r)²]; L=π(R+r)s; S=L+πR²+πr².
Worked example
For R=3 cm, r=0 and h=4 cm, the slant height is 5 cm. Volume: 12π ≈ 37.6991 cm³; surface area: 24π ≈ 75.3982 cm².
Things to check
- The circular bases are parallel and share a perpendicular central axis.
- The upper radius must not exceed the lower radius. Equal radii give the limiting case of a cylinder.
Frequently asked questions
Is the height the same as the slant height?
No. Height is perpendicular to the base; slant height runs diagonally along the side. The calculator distinguishes them.