Concrete Slab Cost Calculator
Get an instant free estimate to pour a concrete slab based on size, thickness, reinforcement, and finish.
Free Concrete Slab Cost Calculator
Use this calculator to calculate the cost of concrete slab near you for free. Enter your ZIP code for a localized estimate.
Slab Dimensions
Enter the length and width of the area.
Slab Thickness:
Reinforcement:
Additional Services:
Estimates are instant and require no contact information.
Based on inputs, your Concrete Slab Installation project cost is approximately:
Note that the cost above is purely an estimate.
The actual cost may be higher or lower depending on the contractor's quote.
How Much Does Concrete Slab Cost?
A basic 4-inch concrete slab runs about $4 to $8 per square foot installed, rising to $6 to $12with reinforcement, a 6-inch pour, or site prep — and $12 to $18+ for a stamped, decorative finish. In whole-project terms, a 400 sq ft (20x20) slab commonly lands near $2,400-$3,600, and a 24x24 garage slab around $4,000-$7,000.
Your square footage and thickness set the base; from there, reinforcement, the sub-base and grading, the finish, and site factors like old-slab removal or a pump truck decide the rest. Small slabs hit a job minimum (around $1,000), so they cost more per square foot. Use the calculator above to localize your estimate, then read on for exactly what drives your quote.
Concrete Slab Cost by Size & Thickness
Typical Total by Common Slab Size
| Slab Size | Area | Typical Installed Cost |
|---|---|---|
| 10 x 10 (shed/AC pad) | 100 sq ft | $1,000 - $1,500 |
| 12 x 12 (patio) | 144 sq ft | $1,000 - $1,800 |
| 20 x 20 (large patio) | 400 sq ft | $2,400 - $3,600 |
| 24 x 24 (2-car garage) | 576 sq ft | $4,000 - $7,000 |
Source: Aggregated installer quote data across U.S. markets; concrete material costs per NRMCA/industry ready-mix pricing, labor anchored to U.S. Bureau of Labor Statistics data for cement masons. Thickness, reinforcement, and site prep move these ranges.
Reinforcement & Add-On Pricing
| Option | Added Cost | When You Need It |
|---|---|---|
| Fiber / Wire Mesh | +$0.40 - $0.50/sq ft | Patios, walkways, light-duty pads. |
| Rebar Grid | +$1.00/sq ft | Driveways, garages, heavy loads. |
| Vapor Barrier | +$0.50/sq ft | Enclosed/interior slabs, finished floors. |
| Stamped Finish | +$8 - $15/sq ft | Decorative patios, curb appeal. |
| Old Slab Removal | +$6/sq ft | Replacing an existing slab. |
| Pump Truck | ~$600 flat | Backyard or no-truck-access pours. |
Source: Aggregated quote ranges from licensed concrete contractors, with regional pricing applied via the calculator above.
The 6 Factors That Drive Your Quote
1. Slab Size (Square Footage)
Concrete is priced per square foot, so length × width sets your base cost — a 10x10 shed pad is a small job, while a 24x24 garage slab is four times the area. Small pours also carry a job minimum (often around $1,000), because mobilizing a crew, forms, and a concrete delivery costs the same whether the slab is tiny or modest. That's why a 6x8 pad can cost more per square foot than a 20x20.
2. Slab Thickness
The standard residential slab is 4 inches, which is fine for patios, walkways, sheds, and foot traffic. Stepping up to 6 inches — needed for driveways, garages, RVs, or anything carrying vehicle weight — uses roughly 50% more concrete plus a deeper base, and raises the per-square-foot rate accordingly. Going thicker than required wastes money; going thinner than the load demands invites cracking, so match thickness to use.
3. Reinforcement
Reinforcement controls cracking and is the cheapest insurance on the slab. Fiber mesh (added to the mix) and welded wire mesh are the economical standards for patios and pads; a rebar grid is the strongest choice and is recommended for driveways, garages, and heavy loads. Skipping reinforcement entirely saves a little upfront but is a common cause of slabs that crack and heave within a few years — it's rarely worth it.
4. Sub-Base & Site Prep
What's under the slab matters as much as the concrete. The crew excavates, grades, and compacts a gravel sub-base, and on damp or interior slabs adds a vapor barrier to block moisture. Sloped lots, poor or clay soil, tree roots, or filling a low spot all add excavation and base material. Inadequate prep is the number-one reason slabs settle and crack, so it's not the place to cut corners.
5. Finish & Sealing
A standard broom finish (lightly textured for grip) is included in the base price. Decorative options cost more: a stamped or stained finish that mimics stone, brick, or tile can add $8-$15+ per square foot, and a smooth or exposed-aggregate finish falls in between. Sealing the surface protects it from stains, de-icing salt, and freeze-thaw damage, and is a small per-square-foot add-on well worth it in cold or wet climates.
6. Access & Old Slab Removal
Site logistics can swing the price. If the truck can't back up to the pour, a concrete pump truck (a flat fee, often around $600) moves the mix over fences or around the house. Tearing out and hauling away an existing slab adds a few dollars per square foot. Tight backyard access, long wheelbarrow runs, and limited staging space all add labor that a simple front-yard pour avoids.
4-Inch vs. 6-Inch — and Do You Need Rebar?
Match the thickness and reinforcement to how the slab will be used — under-building wastes money, under-building it cracks.
4-inch slab with fiber/wire mesh — for…
- Patios and walkways, shed and AC pads, hot tubs, and foot-traffic areas.
- Anything that won't carry vehicle or heavy-equipment weight.
6-inch slab with a rebar grid — for…
- Driveways, garage and workshop floors, RV and boat pads, dumpster pads.
- Any slab that will support vehicles, heavy tools, or a structure above it.
Reinforcement is cheap relative to the slab — skipping it to save a little almost always costs more later in cracking and repairs. If your use is borderline (a future-proofed pad, mixed use), the safer choice is the thicker, reinforced option.
How to Vet and Hire a Concrete Contractor
Most of what makes a slab last is hidden — the base and the prep — so compare on substance, not just the bottom-line price:
- Confirm licensing & insurance (liability and workers' comp) and verify the license with your state board.
- Ask about the sub-base — depth of compacted gravel and how they grade for drainage. Vague answers are a red flag.
- Pin down the concrete mix — PSI strength (3,000-4,000 PSI is typical for slabs) and whether air-entrainment is used in cold climates.
- Check recent local references and photos of slabs a year or more old, so you can see how they held up.
What a complete quote should spell out
- The square footage, thickness (4 in vs 6 in), and reinforcement type (mesh vs rebar).
- Sub-base depth, grading, and vapor barrier where applicable.
- The finish (broom/stamped/sealed) and where control joints will be cut to manage cracking.
- Permit handling, old-slab removal, pump-truck needs, cure-time guidance, and any warranty.
Methodology & Sources
This calculator multiplies your area (length × width) by a per-square-foot rate set by slab thickness (4 in vs 6 in) and reinforcement (none, fiber, wire mesh, or rebar), then adds your selected prep and finishing extras(vapor barrier, grading, stamped finish, sealing, old-slab removal, pump truck). The result is finally adjusted to your ZIP code's regional price level. In short: (Area × [Thickness + Reinforcement Rate]) + Add-ons, × Regional Factor, with a job minimum applied to small pours.
Data sources:
- National Ready Mixed Concrete Association (NRMCA)
- American Concrete Institute (ACI) — slab thickness, reinforcement & jointing
- U.S. Bureau of Labor Statistics — Cement Masons & Concrete Finishers (SOC 47-2051)
For a full explanation of how every calculator on this site is built and localized, see our methodology page.
About the Reviewer
Concrete & Paving Cost Estimator
Senior estimator for concrete flatwork, asphalt paving, and hardscape installations.
View full profile & credentials →Frequently Asked Questions
A basic 4-inch slab typically runs $4-$8 per square foot installed, and $6-$12 once you add reinforcement, a thicker pour, or site prep. Decorative stamped finishes push it to $12-$18+ per square foot. For whole projects, a 400 sq ft (20x20) slab commonly lands around $2,400-$3,600, while a 576 sq ft (24x24) garage slab runs roughly $4,000-$7,000. Small slabs hit a job minimum, so they cost more per square foot.
Installed, expect about $4-$8 per square foot for a standard 4-inch slab with basic reinforcement and prep on an accessible site. A 6-inch slab for vehicles runs higher because of the extra concrete and deeper base. Add-ons stack on top per square foot: vapor barrier (~$0.50), sealing (~$1.50), grading (~$2), old-slab removal (~$6), and a stamped finish (~$12). Remember the job minimum — a very small pad can exceed $8 per square foot on its own.
Use 4 inches for foot-traffic slabs: patios, walkways, shed and AC pads, and standard floors. Step up to 6 inches for anything carrying vehicle or heavy equipment weight — driveways, garage and workshop floors, RV and boat pads, and dumpster pads. The thicker slab needs about 50% more concrete and a deeper compacted base, so it costs more, but a 4-inch slab under a vehicle will crack. When in doubt for a load-bearing use, go 6 inches.
For patios, walkways, and light-duty pads, welded wire mesh or fiber mesh in the mix is usually sufficient and economical. For driveways, garages, and any slab carrying vehicles or heavy loads, a rebar grid is the stronger choice and is what most pros recommend. Reinforcement doesn't stop all cracking, but it holds cracks tight and keeps the slab from separating. Pouring with no reinforcement at all saves little and is a frequent cause of early failure.
A 20x20 slab is 400 sq ft; at a typical installed rate it runs about $2,400-$3,600 for a 4-inch reinforced pour, more with a thicker slab or decorative finish. A 24x24 slab (576 sq ft, a common two-car garage size) usually runs $4,000-$7,000, often at 6 inches with rebar for vehicle weight. Site prep, old-slab removal, and access (pump truck) can move both figures up. Use the calculator above for your exact dimensions and ZIP.
A standard quote usually covers forming, a compacted gravel base, the concrete, basic reinforcement, the pour, and a broom finish. Commonly separate: a vapor barrier, decorative or stamped finishes, sealing, extensive grading or fill, tearing out an old slab, and a pump truck for hard-to-reach pours. Permits may be extra too. Always get the thickness, reinforcement type, base depth, and finish spelled out in writing so you're comparing equivalent quotes.
For exterior slabs like patios and walkways, a vapor barrier usually isn't required. For any slab that will be enclosed or have finished flooring over it — a garage, shed floor, room addition, or interior slab — a 6-mil (or thicker) poly vapor barrier under the concrete is strongly recommended to stop ground moisture from wicking up, which can damage flooring and cause condensation. It's an inexpensive add-on (around $0.50 per square foot) that prevents expensive moisture problems later.
Because the fixed costs of a pour don't shrink with the slab. Mobilizing a crew, building forms, prepping the base, and taking a concrete delivery (which has its own short-load fees) cost roughly the same for a 6x8 pad as for a 12x12. So contractors apply a job minimum — often around $1,000 — meaning small slabs have a high effective per-square-foot cost. If you have several small pads to pour, doing them in one visit lowers the per-slab cost.
A stamped or stained decorative finish typically adds $8-$15+ per square foot over a plain broom finish, sometimes more for multiple colors or intricate patterns, because it's labor-intensive and skilled work. Exposed aggregate and smooth-troweled finishes cost less than full stamping. Decorative concrete can mimic stone, brick, slate, or tile at a fraction of those materials' cost, but budget for periodic resealing to keep the color and protection intact.
You can typically walk on a new slab after 24-48 hours, but keep vehicles off it for about 7 days, and wait the full 28-day cure before parking heavy vehicles or building on it, since that's when concrete reaches its rated strength. Sealing is usually done after the concrete has cured. Pouring in very hot or freezing weather changes these timelines, so follow your contractor's specific cure guidance — rushing it is a common cause of surface cracking.