Concrete slab calculator
Concrete Slab Calculator
Estimate concrete volume and bag quantities for rectangular slabs.
Results
- Base cubic feet
- 33.33 cu ft
- Base cubic yards
- 1.23 cu yd
- Cubic yards including waste
- 1.36 cu yd
- 40 lb bags
- 123 bags
- 60 lb bags
- 82 bags
- 80 lb bags
- 62 bags
10% waste allowance
What this calculator does
This calculator estimates concrete for rectangular slabs using length, width, thickness, quantity, and waste allowance.
Formula used
Base cubic feet equals length in feet x width in feet x thickness in inches divided by 12 x quantity. Cubic yards equal cubic feet divided by 27.
Waste and bag estimates
Waste is added before final volume and bag counts are calculated. Bag estimates use approximate 40 lb, 60 lb, and 80 lb yields and round up to whole bags.