Concrete ordering caveats
Use consistent units for length, width and depth. Real concrete orders may need conversion to cubic yards or cubic meters, minimum delivery amounts, reinforcement allowances and site-specific waste.
Example
A slab that is 10 by 10 by 0.33 units has a base volume of 33 cubic units. With 10% waste, the ordering estimate becomes 36.3 cubic units before any unit conversion.
Common mistakes
Depth is often the problem input. Four inches is 0.333 feet, not 4 feet. Convert thickness into the same unit as length and width before calculating volume.
Limitations
This calculator does not account for reinforcement, excavation, forms, delivery minimums, pump charges or local concrete mix requirements. Use it for volume planning before confirming with a supplier.
Last reviewed: 2026-05-17