Volume Calculator
Calculate the volume of common 3-D shapes — box, cube, sphere, cylinder, cone, pyramid, capsule, ellipsoid and prism — and instantly see the capacity in litres and gallons.
All units
Note: Enter all dimensions in the same unit. Capacity in litres and gallons assumes the shape is a container filled to the brim; US and UK gallons differ and are both shown.
Measure the shape, then calculate its volume
Select the closest supported shape and enter the requested dimensions in the same length unit. For container capacity, measure the inside space rather than the outside walls. The result assumes the selected ideal geometry; wall thickness, fittings, rounded corners and an unfilled gap reduce usable capacity.
Core formulas with worked examples
| Shape | Formula | Example |
|---|---|---|
| Box | length × width × height | 2 × 3 × 4 m = 24 m³ |
| Cylinder | π × radius² × height | radius 0.5 m, height 2 m: 1.5708 m³ |
| Sphere | 4π × radius³ ÷ 3 | radius 1 m: 4.1888 m³ |
| Cone | π × radius² × height ÷ 3 | radius 1 m, height 3 m: 3.1416 m³ |
A cylinder’s radius is half its diameter. Entering a diameter in a radius field multiplies the circular area, and therefore the volume at the same height, by four. Check that distinction before ordering materials.
Capacity and unit conversion
One cubic metre is exactly 1,000 litres. A rectangular tank with internal dimensions 1 m × 0.5 m × 0.4 m has a geometric volume of 0.2 m³ = 200 L when filled to the brim. An operating fill level below the rim gives a smaller usable quantity.
Volume units are cubed: 1 m = 100 cm, but 1 m³ = 1,000,000 cm³. US liquid and imperial gallons also differ. For the same litre amount, divide by 3.785411784 for US gallons or 4.54609 for imperial gallons.
What this geometric estimate excludes
A shape calculation does not establish structural strength, safe tank pressure, HVAC equipment size, material weight or a construction order quantity. Weight needs the material’s appropriate density. Soil and aggregate can settle or compact, and concrete orders may need project-specific allowances. Obtain those assumptions separately rather than treating a geometric volume as a complete specification.
Frequently asked questions
Can I calculate an irregular object?
Break it into non-overlapping simple shapes and add their volumes, subtracting holes or voids. Water displacement is another method only when the object can be safely submerged without absorbing or reacting with the liquid.
How do I calculate an ellipsoid?
Use 4πabc/3, where a, b and c are the three semi-axis lengths. These are half the full widths, not the full diameters.
What does capsule side height mean?
For a capsule consisting of a cylinder and two hemispherical ends, use the length of the straight cylindrical part. The two ends together form one sphere; do not include them again in the cylinder length.
Why does an answer use scientific notation?
It is a compact way to show a very large or small quantity. For example, 2.5e6 means 2.5 × 10⁶, or 2,500,000. It does not make an imprecise input more accurate.
For material planning, see the concrete calculator. For exact gallon definitions, see the US and imperial gallon examples.