Volume of a Torus

Volume = 2(π²R)(r²)

Where:
r = outer radius; distance from inside of ring (outside of hole) to outside of ring
R = inner radius; distance from center of hole to middle of ring

A torus is three-dimensional ring, like a doughnut. The volume of a torus is the amount of space it fills.

To use this calculator, enter the value for the outer radius ("distance from outside of center circle to outside of the tube"), r, and the value for the inner radius ("distance from torus center to center of the tube,") R. For the volume of the torus, press "Find the Volume."

Kinds of tori
Ring torus (where r < R)
Horn torus (where r = R)
Spindle torus (where r > R)

Works Cited
"Torus." Everything2. 30 March 2002. The Everything Development Company. 20
     July 2006. <http://www.everything2.com/index.pl?node_id=71036>.