Bag yields used
- 40 lb bag0.30 cubic feet.
- 50 lb bag0.375 cubic feet.
- 60 lb bag0.45 cubic feet.
- 80 lb bag0.60 cubic feet.
Bag count
Concrete Bag Calculator
Estimate concrete bags by dimensions, bag size and waste factor.
US units
10% default waste
Bag and yard estimates
Concrete estimate
Enter dimensions
Estimate assumptions
- Estimates are for planning and ordering only.
- Bag counts are rounded up to whole bags.
- Ready-mix yards are rounded up to the nearest 0.25 cubic yard.
- Default waste is 10%. Increase it for uneven excavation, spillage, or complex forms.
- Verify structural work with a contractor, engineer, or supplier before pouring.
Buying bags safely
The calculator rounds up to whole bags after adding waste. That is intentional because buying one bag short can stop the job.
Check the yield printed on the bag you are buying. If it differs from the defaults, use the result as a planning estimate and adjust before checkout.
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FAQ
How many 80 lb bags of concrete do I need?
Enter your dimensions and choose 80 lb bags. The calculator uses 0.60 cubic feet per bag and rounds up.
How many 60 lb bags equal one cubic yard?
At 0.45 cubic feet per bag, one cubic yard takes about 60 bags before waste.
Why is the bag count rounded up?
Concrete bags cannot be bought in fractions, and ordering short is usually worse than having a small amount left over.