Volume Calculator

Volume formulas

Prisms and cylinders are base area times height. Pointed shapes — cones and pyramids — hold exactly a third of the prism or cylinder with the same base and height. A frustum is a cone with the top cut off, the shape of most buckets, cups and planters. The spherical cap here takes the radius of its flat base and its height, which are what you can measure on a dome or a bowl. Enter every size in the same unit; the result shows the formula with your numbers in it and, for round shapes, the answer in terms of π.

Cubic units, gallons and liters

The calculator shows all of these at once. For conversions on their own, see gallons to liters and liters to gallons.

Everyday volumes

An aquarium’s listed size is usually the outside volume; the water it holds is a little less because of the glass and the gap at the top. A pool’s gallons decide how much chlorine and how long a fill takes. For a round pool or a tank on its own, the cylinder volume calculator also works backwards from a volume; for balls and round tanks, the sphere calculator; for piles of gravel and cones, the cone volume calculator.

Pipe volume

The water a pipe holds is a cylinder: choose Cylinder, enter half the inside diameter as the radius and the pipe’s length as the height, and read the result in gallons. Use the inside diameter, not the nominal size printed on the pipe, which can differ by a fraction of an inch. For a quick figure, these are the U.S. gallons per foot and per 100 feet for common inside diameters:

Measuring for volume

Measure inside a container for what it holds and outside for the space it takes up. Use the radius — half the diameter — in the round formulas. For a shape that is not on the list, split it into pieces: an L-shaped bed is two boxes, a silo is a cylinder with a cone or a dome on top, and a tank with rounded ends is a capsule. For soil, mulch, gravel and concrete ordered by the cubic yard, the cubic yards calculator handles several areas and depths at once.