How Much Does a Concrete Slab Cost?

A concrete slab costs $4–8 per square foot installed for standard broom-finish work, so the cost of a concrete slab scales directly with its size: a 10×10 pad runs $400–800, a 20×20 slab runs $1,600–3,200, and a 30×30 slab runs $3,600–7,200. Materials by themselves are only $1–2 per square foot — the rest is labor, site preparation, and reinforcement. Use our concrete slab cost calculator to get an exact estimate for your dimensions, thickness, and region.

Concrete Slab Cost by Size

Concrete slab cost scales nearly linearly with square footage at the basic $4–8/sq ft installed range. Read the low end as a simple broom finish in low-cost regions (Midwest, Southeast) and the high end as decorative or structural work in high-cost regions (Northeast, West Coast).

Add 10–25% to these ranges for rebar reinforcement, a vapor barrier, or thickened edges. Add $3–8/sq ft for stamped or decorative finishes. Sites needing significant subgrade work or demolition of existing concrete add another $2–4/sq ft on top.

Cost of a Concrete Slab by Project Type

The cost of a concrete slab varies by project type because each has different size norms, thickness requirements, and finishing complexity.

Sidewalks cost more per square foot because they are narrower — more edge work per area — and often require more reinforcement per linear foot. Driveways and garage floors trend higher when they're thickened to 5–6 inches to carry vehicle loads.

How Much Is Concrete Per Square Foot?

The phrase "how much is concrete per square foot" hides a big gap depending on whether you mean materials only or a finished, installed slab.

The jump from $1–2 to $4–8 is almost entirely labor and site prep. That's why doing the work yourself can cut total cost by 50–60% on a small pour — you're buying back the labor share. For a deeper breakdown of unit pricing by finish type, see our dedicated guide on concrete cost per square foot. For the cost of the concrete itself by volume, see concrete cost per yard.

Concrete Pad Cost vs. Concrete Slab Cost

"Concrete pad" and "concrete slab" describe the same material at different scales — and pricing tracks the scale.

• Concrete pad — small, standalone pours for HVAC condensers, generators, hot tubs, sheds, or trash-bin enclosures. Typically 50–200 sq ft. A 4×8 pad (32 sq ft) for an HVAC condenser typically costs $600–900 installed, though many contractors charge a minimum of $500–800 regardless of size for small pads.
• Concrete slab — larger structural pours: patios, driveways, garage floors, foundations. Typically 300+ sq ft. A 20×20 slab (400 sq ft) costs $1,600–3,200 at the same $4–8/sq ft baseline.

Per-square-foot pricing is comparable (basic broom-finish work runs $4–8/sq ft regardless of size), but two factors push small concrete pad cost above the per-sq-ft baseline: contractor minimums (delivery and labor have fixed costs that don't scale down well below ~$500) and the higher edge-to-area ratio (more form work per square foot of finished concrete). If you're pouring a small pad yourself, our guide on how to pour a small concrete slab covers bag counts and single-person technique.

What Affects the Cost of a Concrete Slab

Five factors move a slab from the low end of the range to the high end.

Thickness

Each additional inch of thickness adds approximately $0.75–1.25 per square foot in material cost, plus minor labor for the heavier pour.

For most residential projects, 4 inches is correct (per IRC R506.2.3 minimum residential slab thickness) — only upgrade to 5–6 inches for driveways that regularly see heavy vehicles.

Reinforcement, Site Prep, and Finish

• Reinforcement — rebar or wire mesh per ACI 332-20 residential concrete construction adds $0.50–1.00/sq ft.
• Site preparation — excavation and a compacted gravel base add $2–3/sq ft; poor subgrade requiring stabilization costs more.
• Finish — a basic broom finish is included in the base rate; stamped, colored, or exposed-aggregate finishes add $3–8/sq ft.

Region

Installed prices vary significantly by region, driven primarily by local labor rates.

Material costs (concrete, rebar, gravel) are relatively consistent nationally — labor is the variable. In high-cost metros, always get 3+ bids; variance between contractors is substantial.

Labor vs. Material Breakdown

For a professionally installed residential slab, costs split roughly 60% labor and overhead, 40% materials.

Labor dominates because concrete work is time-sensitive and physically demanding. A crew of 3–4 can pour and finish a 400 sq ft slab in 4–6 hours, but that's 12–24 labor hours at $40–70/hour. Larger pours exceeding one truck load (about 10 cubic yards per NRMCA standard ready-mix truck capacity) require planned construction joints to divide the work into sections finished within a single set window.

What's Included in a Concrete Slab Quote

A complete slab installation quote should include: excavation to depth, compacted gravel base (4–6 inches), forms (set and remove), reinforcement (rebar or wire mesh per ACI 332-20), concrete materials and delivery, placement and finishing labor, and cleanup.

Items often not included by default:

• Permits — typically $50–200 for residential pours
• Demolition of existing concrete — add $2–4/sq ft
• Decorative finishes — stamped, colored, or exposed aggregate add $3–8/sq ft
• Sealing — recommended for driveways, adds $0.50–1.50/sq ft
• Soil stabilization for poor subgrade — varies by conditions

Always confirm inclusions in writing before signing. Standard residential mix is 3,000–4,000 PSI — confirm the strength spec matches your load.

DIY vs. Hiring a Contractor

DIY concrete work saves 50–60% on labor but has real limits.

DIY makes sense when:

• Volume is under 1 cubic yard (about 45 bags of 80-lb mix — a small patio or shed base)
• You have 3+ helpers available for the day
• Finish quality and long-term performance are less critical

Hire a contractor when:

• Volume exceeds 1 cubic yard (ready-mix delivery is more practical and often cheaper)
• The project is structural (driveway, garage floor, foundation, or retaining wall)
• Surface finish quality matters
• Local code requires a permit

For a detailed comparison, see our DIY vs. contractor guide.

Key Takeaways

• A concrete slab costs $4–8 per square foot installed for basic work; $10–15 for decorative or high-cost metros.
• A 20×20 slab runs $1,600–3,200; a 30×30 slab runs $3,600–7,200.
• Materials are only $1–2/sq ft — labor is ~45% of the installed cost.
• Small concrete pads cost more per square foot than large slabs because of $500–800 contractor minimums and higher edge-to-area ratios.
• Thickness adds $0.75–1.25/sq ft per inch; 4 inches is standard residential per IRC R506.2.3.
• Use a concrete slab cost calculator to estimate your exact total, and get 3+ bids in high-cost regions.

For more, visit our concrete guides hub or read the complete concrete guide.