Concrete Bags Calculator
If you already know the volume you need, enter it here with the yield printed on your bag (cubic feet per bag) to estimate how many bags to buy.
Step 1: Units
Step 2
Enter project measurements
Use decimals if needed (e.g. 3.5).
Step 3
How to use this calculator
Find yield on the product label. Typical 80 lb bags are often near 0.45 ft³; 60 lb bags are smaller. Adjust for your SKU.
What the math is doing
Bag count equals total cubic feet divided by cubic feet per bag, after applying your waste percentage.
Frequently asked questions
Where do I find bag yield?
It is printed on the bag or technical sheet as cubic feet per bag of mixed concrete.
Should I round up?
Yes. Partial bags are not sold, and spillage happens.
Does water change yield?
Too much water weakens concrete; follow the manufacturer’s water range.
Can I blend bag sizes?
Keep mix designs consistent within a pour for uniform strength.