Calculate how many pre-mixed concrete bags (40, 50, 60, 80 lb or 25kg) and total cubic yards you need for slabs, footings, columns, and post holes.
(36.7 cu ft / 1.04 cubic meters)
It takes 45 bags of 80 lb concrete to make one cubic yard (27 cubic feet). One 80 lb bag yields approximately 0.60 cubic feet of mixed concrete.
It takes 60 bags of 60 lb concrete to make one cubic yard. One 60 lb bag yields approximately 0.45 cubic feet.
A 10x10 foot slab poured at 4 inches thick requires 1.23 cubic yards (33.3 cubic feet) of concrete. With 10% waste, you will need approximately 61 bags of 80 lb concrete or 82 bags of 60 lb concrete.
If your project requires more than 1.5 to 2 cubic yards of concrete (more than 60-90 bags of 80 lb concrete), ordering a ready-mix concrete delivery truck is usually more cost-effective and avoids hours of manual mixing labor.
