Home & Cooking
Concrete Bag Calculator
Calculate how many 40, 60, 80, or 90 lb bags of premixed concrete you need for a slab, footing, square column, or cylinder. Includes waste, total weight, and optional cost.
Pour details
Bags needed
82 60 lb bags
Includes 10% waste. Without waste: 75 bags.
Volume (cu ft)
33.33
Volume (cu yd)
1.23
Total weight
4,920 lb
Estimated cost
Add price
Each 60 lb bag yields 0.45 cu ft of mixed concrete. Bag counts always round up so you do not run short mid-pour.
Frequently Asked Questions about the Concrete Bag Calculator
How many cubic feet does each bag of premixed concrete yield?
A 40 lb bag yields about 0.30 cubic feet of mixed concrete, a 60 lb bag yields 0.45, an 80 lb bag yields 0.60, and a 90 lb bag yields 0.675. These are the standard manufacturer-published yields used by Quikrete, Sakrete, and other major brands. The calculator multiplies your pour volume by these yields, then rounds up to whole bags.
Which bag size should I use for my project?
60 lb and 80 lb bags are the workhorses for residential pours. Use 40 lb bags when you need to carry concrete up stairs or work alone in tight spots. 90 lb bags are most cost-efficient per cubic foot but heavy to handle; pick them only when you have a wheelbarrow on site. For pours larger than about 1 cubic yard (roughly 60 bags of 80 lb), ready-mix delivery is usually cheaper than bagged.
Why does the calculator add a waste percentage?
Some concrete spills off the mixer, sticks to tools, or gets thrown away because the mix went off in the wheelbarrow. The default 10% waste catches all of that and the inevitable miscalculation in pour depth. Drop it to 5% for clean, simple slabs or push it to 15% for footings with uneven subgrade or many small pours.
How is the total weight calculated?
The calculator multiplies the final bag count (with waste) by the bag weight, so 62 bags of 80 lb mix come out to 4,960 lb of dry product. That figure helps you plan delivery, decide if a pallet jack or two-person carry is enough, and confirm your truck or trailer can handle the load.
When should I switch from bags to ready-mix concrete?
About 1 cubic yard is the break-even point. At that volume you would need roughly 45 bags of 80 lb mix, which costs about as much as the smallest ready-mix delivery and takes far more time and mixing equipment. Above 2 cubic yards, ready-mix wins on both cost and consistency, since one truck delivers the entire pour in a uniform mix.