Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Calculate volume in cubic feet for a rectangular box or a cylindrical container.
A general-purpose volume calculator for everyday objects, not just construction materials -- supporting both a rectangular box shape and a cylindrical (round) shape, since many real containers (planters, tanks, tubes, drums) are round rather than rectangular.
Choose Rectangular or Cylindrical. For a rectangular shape, enter length, width, and height. For a cylindrical shape, enter the diameter and height -- no width field is needed since a cylinder's cross-section is defined by one diameter, not two separate dimensions.
Rectangular: Volume = Length × Width × Height
Cylindrical: Volume = π × (Diameter÷2)² × Height
The cylindrical formula is the standard geometric volume of a cylinder, using the radius (half the diameter) squared -- the same formula used by the Concrete Column Calculator for a round concrete pier, just applied here to any round container.
Use this for a garden planter, a fish tank or pond liner, a storage bin, a section of pipe or tube, or any everyday volume question that isn't specifically a construction-material order (for those, see the material-specific calculators like Gravel or Topsoil).
A hypothetical storage bin is 3 feet long, 2 feet wide, and 2.5 feet tall. Its volume is 3 x 2 x 2.5, which is 15 cubic feet. If you need cubic yards, divide by 27 to get about 0.56. If you need liters, multiply cubic feet by about 28.3, which gives roughly 425 liters. Keep the conversion method in mind when you need a different unit.
A hypothetical round water tank is 4 feet across and 5 feet tall. The radius is 2 feet, so the base area is pi x 2 x 2, about 12.57 square feet, and the volume is about 62.8 cubic feet. To convert to US gallons, multiply cubic feet by about 7.48, which gives roughly 470 gallons. That is the total capacity, and the usable volume is less if the tank cannot be filled to the very top.
For storage, shipping, or fluid capacity, the interior dimensions matter. For displacement, such as how much space an object takes up in a truck, the exterior dimensions matter. Decide which you want before you measure, and note that the formula treats the shape as solid with straight sides.
The calculator handles only boxes and cylinders. Spheres, cones, and irregular shapes need different formulas. It reports pure geometric volume, so it does not account for the contents, packing gaps, weight, or fill level. For construction materials that need weight, waste, or compaction, use a material-specific calculator instead.
Measure the diameter across the top (or the widest point) and the height, select "Cylindrical," and enter both -- the calculator applies the standard cylinder volume formula automatically.
This tool reports cubic feet as the primary unit and supports cylindrical shapes; the Cubic Yard Calculator reports cubic yards and supports mixed feet/inch input per dimension for rectangular shapes only -- useful for larger construction-scale volumes.
Multiply by about 7.48 for US liquid gallons. This applies to liquids, and other gallon definitions differ.
Enter the height of the part you want the volume of. If a tank is only filled halfway, enter the liquid height to get the volume of the contents.
Only if it is roughly a box or a circular cylinder. Ponds with sloping sides need an average depth or a more complex calculation.
Because volume depends on the radius squared. Doubling the diameter multiplies the volume by four for the same height.