Concrete Bag Yield Calculator
Translate cubic feet of concrete into the number of pre-mix bags you need at 40, 60, or 80 lb per bag.
Result
Bags of 80 lb pre-mix
17 bags
1,360 lb total weight.
- Per-bag yield0.60 ft³
- Volume incl. waste9.90 ft³
- Total dry weight1,360 lb (0.68 tons)
Step-by-step
- Add waste: 9.00 × 1.10 = 9.90 ft³.
- Divide by bag yield: 9.90 ÷ 0.6 = 16.50 bags.
- Round up to whole bags: 17.
How to use this calculator
- Enter the volume of concrete you need in cubic feet.
- Pick a bag size — 80 lb is the most economical for medium jobs, 60 lb easier to lift.
- Read the bag count and total weight.
About this calculator
Pre-mix bags are convenient for small repairs but get expensive fast — about 1 yd³ per ~45 bags of 80-lb mix. Use bags for posts, repairs, and small pads under ~1 yd³; switch to a ready-mix truck above that. The yields here come from manufacturer data: a 40-lb bag yields ~0.30 ft³, 60-lb ~0.45 ft³, 80-lb ~0.60 ft³.
Frequently asked
At about 1 cubic yard (around 45 80-lb bags). Below that, bags are usually cheaper than the short-load surcharge a ready-mix plant charges.
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