Concrete Calculator
Figure out exactly how much concrete a slab, patio, or footing needs — in cubic feet, cubic yards, and bags — plus a cost estimate.
4″ slab · 6″ patio · 12″ footing
Optional — used for the cost estimate
Total volume (with waste)36.67 ft³ · 1.36 yd³
40-lb bags123 bags · $738
60-lb bags82 bags · $492
80-lb bags62 bags · $372
80-lb bag ≈ 0.60 ft³ (0.022 yd³) · 60-lb ≈ 0.45 ft³ · 40-lb ≈ 0.30 ft³. For ready-mix, order by cubic yard and add 10% for grade variance.