Concrete calculator

Estimate the concrete needed for a slab, with an allowance for spills and uneven ground.

UnitsSlab length (ft)Slab width (ft)Thickness (inches)Waste allowance (%)

Concrete needed

1.36 cubic yards

Cubic feet
36.7

80 lb bags
62

Bag yields are approximate. Large pours are usually ordered as ready-mix by the cubic yard or cubic metre. Estimates only.