Concrete Slab Cost Calculator
Enter your slab's length, width, and thickness along with local ready-mix concrete and labor prices to estimate the material cost, labor cost, and total cost of pouring a concrete slab.
How to calculate concrete slab cost
First find the slab's area (length × width), then multiply by the thickness in feet to get cubic feet, and divide by 27 to get cubic yards, how ready-mix concrete is sold. Multiply the cubic yards by your local cost per cubic yard for the material cost. Multiply the square footage by your labor/finishing rate per square foot for the labor cost. Add the two together for the total project cost. Thickness is usually entered in inches, so divide by 12 to get feet first.
Cubic yards = (Length ft × Width ft × Thickness ft) ÷ 27; Total cost = (Cubic yards × $/yd³) + (Sq ft × Labor $/sq ft)
Worked example
A 20 ft × 20 ft slab, 4 inches thick, with $150 per cubic yard ready-mix concrete and $3 per sq ft labor.
- Sq ft = 20 × 20 = 400 ft²
- Thickness = 4 in ÷ 12 = 0.3333 ft
- Cubic feet = 400 × 0.3333 = 133.33 ft³
- Cubic yards = 133.33 ÷ 27 = 4.94 yd³
- Material cost = 4.94 × $150 = $740.74
- Labor cost = 400 × $3 = $1,200.00
- Total cost = $740.74 + $1,200.00
Result: About $1,940.74 total (roughly $740.74 material, $1,200.00 labor).
Frequently asked questions
How much does a concrete slab cost?
It depends on the slab's size and thickness plus your local material and labor rates, which is why a single national number is misleading. Enter your slab's dimensions and local prices above for a real estimate; a 20 × 20 ft, 4-inch slab at $150/yd³ concrete and $3/sq ft labor comes to about $1,940.74 total.
How much does a cubic yard of concrete cost?
Ready-mix concrete commonly runs somewhere in the $110 to $175 per cubic yard range nationally as of recent years, though it swings with cement prices, region, and delivery minimums. Always confirm the current price with a local supplier before budgeting a job.
How thick should a concrete slab be?
A standard 4-inch slab is typical for patios, walkways, and sheds. Driveways that carry vehicle weight commonly use 5 to 6 inches, and areas expecting heavy trucks may need more along with reinforcement.
Is this a quote or an estimate?
This is a planning estimate, not a quote. Concrete and labor costs vary significantly by region, season, and contractor, and this tool does not include extras like excavation, a gravel base, rebar or wire mesh, forms, or permits. Get a written quote from a local contractor before committing to a budget.
What else affects the total cost of a concrete slab?
Beyond material and labor, budget for site prep (grading and a compacted gravel base), reinforcement (rebar or wire mesh), forms, a vapor barrier if it's a living space, control joints, and any finish like a broom texture, stamp, or stain. Permits and delivery fees can add more.
How many bags of concrete equal a cubic yard?
It takes about 45 bags of 60 lb pre-mixed concrete, or about 60 bags of 40 lb bags, to equal one cubic yard. Bagged concrete is far more expensive per yard than ready-mix delivery, so bags only make sense for small jobs like footings or post holes.