Volume Calculator

This page calculates the volume of a sphere, right circular cone or cube from linear dimensions. Every dimension is converted to metres before the selected geometric formula is applied, so the result is consistently reported in cubic metres.

Volume measures three-dimensional space. A length-unit conversion is cubed in a volume calculation: one centimetre is 0.01 metre, but one cubic centimetre is 0.000001 cubic metre. That distinction explains why a seemingly small unit mistake can produce a very large error.

1. Choose the form for the solid you want to calculate.
2. For a sphere, enter its radius and unit.
3. For a cone, enter base radius and perpendicular height, selecting a unit for each.
4. For a cube, enter one edge length and its unit.
5. Select Calculate and read the result in m³.

All dimensions must be positive numbers. Radius is half the diameter, and cone height means the perpendicular distance from the base plane to the tip rather than the sloping side.

For mixed cone units, the calculator converts radius and height separately. Keep enough decimal places when measuring small objects because the final value is sensitive to every dimension.

The calculated figure is an ideal geometric volume. Real containers may have wall thickness, rounded corners, seams, tapers or unusable space that the simple solid does not include.

For capacity planning, distinguish internal dimensions from external dimensions. External measurements overstate the space inside a tank, box or mould whenever walls have appreciable thickness.

The cube calculator applies to equal edges. A rectangular box with different length, width and height needs V = lwh and should not be forced into the cube form.

The cone equation assumes a circular base and a tip centered over the base. An oblique cone has the same formula when h is the perpendicular height, but measuring along the sloping side is still wrong.

Cubic metres can be converted to litres using 1 m³ = 1,000 L. Do that after calculating rather than treating a linear unit as though it were a volume unit.

Rounding deserves attention with tiny parts. A result below 0.0000005 m³ may display as zero at six decimal places even though the mathematical volume is positive. Use the formula or a smaller cubic unit when that precision matters.

Measurement uncertainty grows through powers. A small radius error affects a sphere through r³ and a cone through r². Do not report more reliable digits than the source measurements justify.

For material orders, volume is only one part of the estimate. Add a documented allowance for waste, compaction, voids or spillage when the project requires it rather than hiding that allowance inside a dimension.

A useful plausibility check is to compare related solids. A cone with a given circular base and height has one-third the volume of the cylinder with that same base and height. A sphere with radius r fits inside a cube of side 2r, so its volume must be less than 8r³. These comparisons catch misplaced factors without repeating the entire calculation.