Construction & Materials
Concrete Slab Calculator
Estimate the concrete volume, cubic yards and 80 lb bag count needed for a rectangular slab.
Your inputs
Change any value to update the result instantly.
Concrete needed
2.716 yd³
Raw volume
2.47 yd³
80 lb bags required
123 bags
60 lb bags required
163 bags
Total slab area
200 ft²
Formula and working
volume = length × width × thickness
- 1
Collect the inputs
Slab length = 20 ft; Slab width = 10 ft; Thickness = 4 in; Waste allowance = 10 %
- 2
Apply the formula
volume = length × width × thickness
- 3
Result
Concrete needed = 2.716 yd³
Frequently asked questions
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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