Radius must match height units
Use the same length unit for radius and height. If you have diameter, divide it by 2 before entering radius.
Example
For a cylinder with radius 3 and height 10, volume is pi x 3 x 3 x 10, or about 282.74 cubic units.
Volume vs surface area
Use volume for tanks, pipes, containers and fill estimates. Use surface area when estimating coating or material around the outside.
Common mistakes
Do not enter diameter as radius. If a cylinder is 6 units across, the radius is 3. Also make sure height and radius use the same unit.
Last reviewed: 2026-05-17