Calculator

Concrete Volume Calculator

Estimate cubic feet and cubic yards of concrete for a rectangular slab, including an optional waste allowance.

Your inputs

Enter the values

ft
ft
in
%

Your result will appear here

Complete the fields and choose Calculate. We’ll show the answer and the working.

How to use the Concrete Volume Calculator

Estimate cubic feet and cubic yards of concrete for a rectangular slab, including an optional waste allowance. Enter the requested values, review their units, and select Calculate. The result panel shows both the answer and the substituted steps.

The formula

volume = length × width × depth

Frequently asked questions

Why add a waste allowance?

Excavation variation, form dimensions, spillage, and finishing can make the placed quantity exceed ideal geometric volume.

How many cubic feet are in a cubic yard?

One cubic yard contains exactly 27 cubic feet.

Important notes

Results are estimates based on the values supplied and the formula shown. Round only at the end of a calculation, and verify safety-critical, medical, financial, or construction decisions with an appropriate professional.

Editorial details

Reviewed for clarity

Written by Krishna. Last reviewed August 3, 2026.