Concrete Calculator

Estimate concrete volume for common rectangular and circular forms, then convert the result into liters, cubic yards and approximate mass.

Rectangular forms

For a slab, footing or wall, multiply length × width × thickness and then multiply by quantity.

Round footings

For a circular footing or column, use the cylinder formula: π × radius² × height × quantity.

Circular slabs and tubes

For a ring-shaped form, subtract the inner circular area from the outer circular area and multiply by length or height.

Why order more than the exact estimate

Actual jobs can involve uneven excavation, spillage, form movement and measurement tolerances. A contractor may choose an appropriate allowance rather than ordering exactly the theoretical volume.

Density and mass

The calculator uses a user-supplied concrete density to estimate mass. Density varies by mix and aggregate, so the volume is the more fundamental result.

Practical use

Use the result for preliminary material planning, then confirm dimensions, mix requirements and local supplier quantities before ordering.