Concrete Volume Calculator

This calculator figures out how much concrete you need for a slab, column, or footing, so you can order the right amount of ready-mix or buy the right number of bags.

For slabs and footings, it multiplies length × width × depth (converted from inches to feet) to get cubic feet, then divides by 27 to convert to cubic yards. For round columns, it uses the cylinder formula: π × radius² × height.

Example: A 10 ft × 10 ft slab poured 4 inches deep works out to 10 × 10 × (4/12) = 33.3 cubic feet, or about 1.23 cubic yards — roughly 74 bags of 60 lb concrete mix.