1). Recall the formula for the volume of a cylinder:
Volume = (pi) x (radius of the round end)² x (length or height) .
2). Gather together the number you'll use for pi, the radius of the cylinder's round end, and its length or height. Make sure that the radius of the round end and the length or height are in the same units. If they're not, then convert something so that they are.
3). Write each number into its place in the formula.
4). Perform the indicated operations. The final number is the volume of your cylinder.