Concrete Calculator

Estimate concrete volume in cubic yards and add a configurable waste allowance.

Results will appear here.

Planning estimate only. Verify dimensions, waste, coverage, product specifications, and local requirements before purchasing materials.

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How this calculator works

Reviewed July 2026

Formula

Cubic feet = length × width × depth in feet. Cubic yards = cubic feet ÷ 27. The waste allowance is then added.

Worked example

For a 20 ft × 10 ft slab at 4 inches deep, convert depth to 0.333 ft before calculating volume and adding the chosen waste allowance.

Frequently asked questions

Why divide by 27?

One cubic yard contains 27 cubic feet.

How much extra concrete should I order?

Many projects include an allowance for uneven excavation and handling, but the right amount depends on site conditions.

Can this calculate footings separately?

Calculate each rectangular section independently and add the volumes before ordering.

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