Concrete
Concrete Slab Cost Calculator
This calculator estimates the material and labor cost of a rectangular concrete slab. Prices vary widely by region and season, so replace the default prices with quotes from local ready-mix suppliers and contractors.
Formula
Concrete (yd³) = length × width × thickness (in) ÷ 12 ÷ 27 × (1 + waste%). Material cost = yd³ × price per yd³. Labor cost = area (ft²) × labor rate. Total = material + labor.
Worked example
A 24 ft by 24 ft garage slab, 4 in thick: area = 576 ft². Concrete = 576 × 4 ÷ 12 ÷ 27 × 1.10 = 7.82 yd³. At $175/yd³ the concrete costs $1,368.89. Labor at $5/ft² is $2,880. Estimated total is $4,248.89, or about $7.38/ft².
Assumptions and limits
- Default prices are placeholders, not market data. Use local quotes.
- Excludes permits, excavation, gravel base, vapor barrier, reinforcement, pump truck, short-load fees and demolition.
- Labor rate is assumed to include forming, placing, finishing and curing.
Frequently asked questions
What is a short-load fee?
Many ready-mix suppliers charge an extra fee for orders below a minimum (often several cubic yards) because the truck trip costs the same. Ask your supplier for its minimum before ordering a small pour.
Does reinforcement change the cost much?
Wire mesh or rebar adds material and labor, typically a modest share of the total for a residential slab. Use the rebar calculator to estimate bar quantity.
Why is my quote higher than this estimate?
Quotes include items this calculator leaves out, such as site prep, base gravel, pumping, permits, overhead and profit. Access, slope and travel distance also matter.