How do you calculate the radius and height of a cylinder if you know the volume?

Answer 1

Without knowing either the radius or the height (or some method to find one of them) you can't calculate both of them using just the volume.

The equation for the volume of a cylinder is V = pi * r^2 * h
From this we can say that: V/pi = r^2 * h


You might already see the problem - how do we solve for both r and h? I can create a short cylinder with a large radius that has the same volume as a tall cylinder with a small radius. Both would have the same volume, but would have very different values for r and h. Unless you know (or can find) either r or h, you can't solve this problem.


If you DO know one, you can do the following:
If you know r, then h = V/(pi * r)
If you know h, then r = sqrt(V/(pi * h))


Hope this helps!