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Concrete Slab
Cubic yards of concrete for a slab, pad or footing, with waste and bag equivalents.
Enter width and length to see results.
Assumptions
- An 80 lb bag yields about 0.60 CF; a 60 lb bag about 0.45 CF.
- Ready-mix is sold by the yard, usually in quarter-yard increments — round up.
Common questions
How many yards of concrete for a 10×10 slab 4 inches thick?
10 × 10 × (4 ÷ 12) ÷ 27 = 1.23 CY. With 5% waste, order 1.3 CY, or about 58 bags of 80 lb mix.
How do I calculate cubic yards of concrete?
Length (ft) × width (ft) × thickness (ft) ÷ 27. Convert inches to feet by dividing by 12.
Planning numbers. Confirm quantities with your supplier, spec and local conditions before ordering.
Running a crew?HardHatOps — toolbox talks, time clock, sign-off records, daily duties. The field side.
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