Concrete Bag Calculator
Calculate how many bags of concrete are needed for a given volume.
Formula & Explanation
This calculator converts a volume of concrete (in cubic feet) to the number of bags required. First, we add the waste percentage to the volume: Volume with Waste = Volume × (1 + Waste% / 100) Then, we divide by the bag yield to find the number of bags: Bags Needed = ceil(Volume with Waste ÷ Bag Yield) Common bag yields are: - 60 lb bag: ~0.45 cu ft - 80 lb bag: ~0.60 cu ft The result is rounded up because you cannot buy a partial bag.
Assumptions
- •The input volume is already calculated from your project dimensions (use other calculators for slabs, walls, etc.)
- •Bag yield values are industry standards-confirm with your specific concrete product
- •A 10% waste allowance is typical; adjust based on site conditions
- •The calculator rounds up to the nearest whole bag
Example Calculation
For 100 cubic feet of concrete, with 10% waste allowance, using 60 lb bags (0.45 cu ft yield), you need 245 bags.
Inputs
Results
Concrete Volume to Bag Conversions (60 lb bags, 0.45 cu ft yield, 10% waste)
| volume_cuft | volume_cuyd | bags_needed |
|---|---|---|
| 10 | 0.37 | 25 |
| 25 | 0.93 | 62 |
| 50 | 1.85 | 123 |
| 100 | 3.70 | 245 |
| 150 | 5.56 | 368 |
Frequently Asked Questions
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