How Many Bags of Concrete Do I Need?
Each 80 lb bag yields about 0.6 cubic feet, a 60 lb bag about 0.45 cubic feet, and a 40 lb bag about 0.3 cubic feet.
Bag yields
Divide the total volume in cubic feet by the yield per bag to get the number of bags.
One cubic yard (27 cubic feet) takes roughly 45 bags of 80 lb, 60 bags of 60 lb, or 90 bags of 40 lb.
Worked example
A project needing 12 cubic feet of concrete takes 12 ÷ 0.6 = 20 bags of 80 lb mix.
Always buy one or two extra bags to cover spillage and slightly deep spots.
FAQs
- Is it cheaper to buy bags or ready-mix?
- Bags cost more per yard but make sense for small jobs where a ready-mix truck minimum would be wasteful.