Poured concrete slab cost typically runs $6-$12 per square foot installed, with a common 400-square-foot slab totaling about $3,200. Thickness, reinforcement, site preparation, access, and local labor rates can push a quote below or above that range.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Installed slab | $6/sq ft | $8/sq ft | $12/sq ft | Basic residential work, standard access |
| 400-sq-ft slab | $2,400 | $3,200 | $4,800 | About 20 by 20 feet |
| Reinforced or thicker slab | $9/sq ft | $12/sq ft | $15+/sq ft | For heavier loads or demanding site conditions |
| Concrete only | $125/cu yd | $160/cu yd | $200+/cu yd | Delivery and local supplier rates affect price |
What a poured slab costs by square footage
A straightforward residential slab generally costs $6-$12 per square foot for concrete, forming, placement, and basic finishing. A 10-by-10-foot pad may cost $600-$1,200, while a 20-by-30-foot slab may run $3,600-$7,200. Small projects can cost more per square foot because contractors still have mobilization and minimum-charge expenses.
These figures assume a level, accessible site, ordinary ready-mix concrete, and no major excavation or demolition. A garage floor, shed pad, patio, or equipment base may need different thickness and reinforcement. Assumptions: standard residential mix, typical U.S. labor rates, normal access, and no major drainage work. For early budgeting, $8 per square foot is a reasonable midpoint for a basic slab.
How forming, concrete, and labor shape the quote
Contractor estimates divide the job among materials, crew time, and site work. The table shows common portions of the installed price; actual shares vary with slab size, concrete volume, and local conditions.
| Cost component | Typical range | What it covers | Unit or pricing note |
|---|---|---|---|
| Concrete and delivery | $2-$4/sq ft | Ready-mix, short-load charges, placement supply | Concrete often $125-$200+/cu yd |
| Labor and finishing | $2-$5/sq ft | Forming, pouring, leveling, jointing, finishing | $50-$100 per crew hour, region dependent |
| Base and reinforcement | $1-$3/sq ft | Gravel, wire mesh or rebar, vapor barrier | Depends on thickness and design |
| Equipment and site work | $1-$4/sq ft | Compaction, grading, pump or machine access | Can rise with difficult access |
| Removal and disposal | $2-$6/sq ft | Breaking and hauling an existing slab | Usually additional to replacement slab |
Concrete volume is estimated by multiplying length by width by thickness, then converting cubic feet to cubic yards. For example, a 400-square-foot slab at 4 inches thick requires about 4.9 cubic yards before allowing for waste. Ask whether the quote includes base preparation, reinforcement, delivery, finishing, and cleanup.
Thickness, rebar, and grading can change slab pricing
A 4-inch slab is common for patios and light residential use, while heavier vehicle or equipment loads may call for 5-6 inches or an engineer’s specifications. Increasing thickness from 4 to 6 inches raises concrete volume by 50%, though the full installed cost does not necessarily rise by the same percentage. Reinforcement, thicker edges, or a stronger mix can add roughly $1-$4 per square foot.
Site work is another major swing. Minor leveling may add $0.50-$2 per square foot; excavation, poor soil, a sloped lot, or substantial gravel fill can add $2-$8 or more per square foot. Slabs larger than roughly 600 square feet may also need control joints and careful placement planning. Confirm the slab’s intended load and thickness before comparing bids.
Regional concrete rates differ across U.S. markets
Labor availability, aggregate supply, delivery distance, and local building requirements affect estimates. In lower-cost rural markets, a basic slab may land 10%-20% below the national midpoint. Major metro areas and high-cost coastal markets often run 15%-35% higher; remote sites can also cost more when concrete trucks travel farther or a short load is required.
These percentages are budgeting comparisons, not fixed regional surcharges. A nearby ready-mix plant and a contractor with an available crew can matter more than the state average. Compare local quotes for the same dimensions, thickness, base, reinforcement, and finish.
How long a residential slab pour takes
For a typical 300-500-square-foot slab, a crew of three to five workers may spend 1-2 days on forming and preparation, then several hours placing and finishing the concrete. Excavation or complicated grading can add another day or more. The slab needs protection while curing; foot traffic is commonly delayed for at least 24-48 hours, and vehicles usually require more time based on the mix and weather.
Labor rates commonly fall around $50-$100 per crew hour, but contractors usually quote the entire job rather than hourly billing. Weather, truck arrival timing, and access for a concrete pump can affect the schedule and price. A low labor estimate should still account for forming, placement, finishing, and cleanup.
Lower the slab price by controlling scope and prep
Keeping the slab rectangular, selecting only the thickness required for its use, and avoiding unnecessary decorative finishes can limit labor and material costs. Clearing vegetation and providing clear equipment access may reduce preparation charges, but excavation and compaction should follow the contractor’s specifications rather than being skipped.
Request at least three itemized quotes and compare the same concrete strength, dimensions, reinforcement, base depth, finish, and disposal scope. Combining nearby work may reduce mobilization fees, while scheduling outside peak construction periods can improve contractor availability. Do not cut required drainage, subgrade compaction, or reinforcement just to lower the initial quote.
Three slab estimates for common residential projects
A 120-square-foot shed pad, 4 inches thick, with basic grading and a broom finish might cost $1,000-$1,800. A 400-square-foot patio with a gravel base and mesh could run $3,200-$5,200. A 600-square-foot garage slab, 5 inches thick with rebar and more extensive grading, may cost $6,000-$10,000. These examples reflect typical installed ranges, not guaranteed bids.
A small job can have a high per-square-foot price even when its total is modest. Larger projects spread delivery and crew setup costs over more area, but heavier reinforcement or extra excavation can offset those savings. Use dimensions and written scope—not only the total—to judge whether estimates are comparable.
Existing concrete removal adds a separate expense
Breaking up and hauling away an old slab commonly adds $2-$6 per square foot, with thick concrete, embedded rebar, restricted access, or distant disposal sites increasing the charge. A 400-square-foot removal could therefore add about $800-$2,400 before the replacement slab is poured. Some contractors price demolition by the project or truckload instead.
Permits and inspections depend on local rules and the slab’s purpose, size, drainage impact, and connection to a garage or addition. Permit fees may range from about $50-$500 or more, and code-related drainage or foundation work is separate. Check local requirements and ask whether removal, hauling, permits, and inspection fees are included in the estimate.