Volume calculator

The formulas

• Box: length x width x height.
• Cylinder: π x (diameter / 2)² x height.
• Cone: one third of the cylinder with the same base and height.
• Sphere: π x diameter³ / 6, the same as 4/3 x π x radius³.
• Pyramid: length x width x height / 3.
• Wedge: the triangle's base x its height / 2, times the length of the wedge.

Measure every size in the same unit. The answer comes out in that unit cubed and is then converted.

Cubic yards and cubic metres

Soil, gravel, mulch and ready-mix concrete are sold by the cubic yard in the US and by the cubic metre elsewhere. A cubic yard is 3 ft x 3 ft x 3 ft, which is 27 cubic feet or 0.7646 m³. A cubic metre is 1,000 litres.

Worked example

A box 6 ft x 4 ft x 2 ft is 48 cubic feet. 48 / 27 = 1.78 cubic yards. In metric, 48 x 0.0283168 = 1.359 m³, or 1,359 litres. A US gallon is 231 cubic inches (3.785 litres), so 48 cu ft holds about 359 US gallons.

Liquids

Gallons here are a straight conversion of the space inside. A tank's working capacity is usually less, so check its label. To buy materials with an allowance for waste, use the concrete, gravel or topsoil calculators.