Concrete Calculator

Calculate concrete volume for slabs, strip footings, and round columns — then convert to cubic yards, 80-lb bag counts, and estimated ready-mix delivery cost. Includes automatic 10% overage for spillage, uneven subgrade, and form overflow.

Construction searches peak during spring and summer building season. Contractors and DIYers need quick volume estimates before ordering from the plant — ordering short means cold joints and structural weakness; ordering long wastes hundreds of dollars on unused mix.

Switch between metric and imperial inputs. Choose shape type (slab, footing, column) for accurate geometry formulas. One cubic yard equals 27 cubic feet; an 80-lb bag yields roughly 0.6 cubic feet when mixed.

Typical patio slab: 12 ft × 16 ft × 4 in thick ≈ 2.4 cubic yards before waste. Post holes and footings add up quickly — calculate each section separately and sum totals for your order.

Double-check critical structural pours with a licensed engineer or contractor — this tool estimates volume for planning and budgeting, not load-bearing design.