What is included in this estimate?
The calculation measures slab area in square feet and determines cubic yards of concrete from length × width × thickness, including your waste percentage. Material cost is cubic yards × your price per cubic yard. Labor cost is square feet × your chosen labor price. Site preparation, reinforcement, delivery and additional costs are added as editable project-wide allowances.
Worked cost example — illustrative prices only
For a 20 × 10 ft slab, 4 in deep, area is 200 sq ft and concrete with 10% extra is about 2.72 cubic yards. If you enter $150/cubic yard for concrete and $4/sq ft for labor, those components are about $407.41 and $800.00 respectively. Adding preparation ($200), reinforcement ($150), delivery ($50) and other costs ($25) gives $1,632.41 in this hypothetical scenario. These are demonstration inputs, not observed current US prices.
Why real slab prices vary
Demolition, gravel base, vapor barriers, formwork, finishing, reinforcement type, equipment, permits, access, minimum deliveries and geographic labor rates all affect a project. Obtain itemized local quotes. This estimator does not calculate excavation quantities, reinforcement design, or engineering specifications.
Is the cost per square foot a contractor quote?
No. It is total editable estimate divided by the calculated slab surface area.