Concrete Slab Cost Calculator
A typical concrete slab costs $4–8 per square foot installed. A 20×20 patio runs $1,600–3,200; a 12×60 driveway runs $2,880–7,200. Enter your dimensions to get a full cost breakdown by materials, labor, region, and thickness.
Pro Tips
- →Basic slab installation costs $4-8 per square foot
- →Thicker slabs increase both material and labor costs
- →Add $1-2 per square foot for reinforcement
- →Site preparation adds $2-3 per square foot
- →Decorative finishes add $2-4 per square foot
Estimated concrete cost (materials + delivery) · For projects over 1 cubic yard, ready-mix is typically more economical and easier to work with.
245 bags × 80lb
5.43 cubic yards + delivery
400 sq ft × $3.00–$8.00/sq ft
Prices vary by location and time. Contact local suppliers for accurate quotes.
That's typically a professional pour. See volume ↓
4 short emails from Dave: what a fair quote should land at for your slab, the scope changes that swing it ±$500, and whether DIY is actually cheaper at your volume. Reply anytime — he'll review your real quote.
Includes 10% waste factor
For general step-by-step instructions, read our complete Concrete Cost Per Square Foot and Diy Vs Contractor.
Concrete Slab Costs by Project Type
Concrete slab pricing varies by project type because each has different size norms, thickness requirements, and finishing complexity.
| Project Type | Typical Size | Thickness | Installed Cost |
|---|---|---|---|
| Patio | 12×12 to 20×20 ft | 4 in | $4–8/sq ft |
| Driveway | 10×20 to 12×60 ft | 4–5 in | $5–10/sq ft |
| Garage floor | 20×20 to 24×30 ft | 4–6 in | $4–9/sq ft |
| Sidewalk | 4×20 to 6×60 ft | 4 in | $6–12/sq ft |
| Foundation slab | Full footprint | 4–6 in | $4–7/sq ft |
Sidewalks cost more per square foot because they are narrower — more edge work per area — and often require more reinforcement per linear foot.
Concrete Slab Cost by Size
Concrete slab cost scales linearly with square footage at the basic $4–8/sq ft installed range. The table below covers the most common project sizes — 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).
| Slab Size | Square Feet | Installed Cost ($4–8/sq ft) |
|---|---|---|
| 10×10 ft | 100 | $400–800 |
| 12×12 ft | 144 | $576–1,152 |
| 16×20 ft | 320 | $1,280–2,560 |
| 20×20 ft | 400 | $1,600–3,200 |
| 24×24 ft | 576 | $2,304–4,608 |
| 24×25 ft | 600 | $2,400–4,800 |
| 30×30 ft | 900 | $3,600–7,200 |
| 30×45 ft | 1,350 | $5,400–10,800 |
| 40×40 ft (1,600 sq ft) | 1,600 | $6,400–12,800 |
Add 10–25% to these ranges for rebar reinforcement, 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.
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 pads 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).
How Thickness Affects Cost
Each additional inch of thickness adds approximately $0.75–1.25 per square foot in material cost, plus minor labor increases for the heavier pour.
| Thickness | Concrete Per 100 sq ft | Material Cost (100 sq ft) | Typical Use |
|---|---|---|---|
| 3 in | 0.93 cu yd | $150–225 | Light foot traffic only; not recommended for vehicles |
| 4 in | 1.23 cu yd | $195–295 | Standard residential — patios, walkways, garage floors |
| 5 in | 1.54 cu yd | $245–370 | Heavier vehicles, occasional truck traffic |
| 6 in | 1.85 cu yd | $295–445 | Heavy loads, commercial, freeze-thaw climates |
Going from 4 to 6 inches adds roughly $100–150 in material cost per 100 sq ft. 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.
Labor vs. Material Breakdown
For a professionally installed residential slab, costs split roughly 60% labor and 40% materials.
| Cost Component | Share | Per sq ft (typical) |
|---|---|---|
| Concrete materials | ~30% | $1.50–2.50 |
| Site prep and forms | ~15% | $0.75–1.50 |
| Reinforcement (rebar or mesh) | ~10% | $0.50–1.00 |
| Labor (pour and finish) | ~45% | $2.25–4.00 |
| Total installed | 100% | $5–9 |
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 total 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 that can be finished within a single set window.
Regional Cost Variation
Installed concrete slab prices vary significantly by region, driven primarily by local labor rates.
| Region | Typical Installed (4-in slab) |
|---|---|
| Northeast (NY, MA, CT) | $7–12/sq ft |
| West Coast (CA, WA, OR) | $7–11/sq ft |
| Midwest | $5–8/sq ft |
| Southeast | $4–7/sq ft |
| Mountain West | $5–9/sq ft |
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.
What's Included (and What's Not) in a Contractor 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 residential concrete construction), 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.
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
- The 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, concrete cost per square foot guide, and the concrete walls hub for wall and retaining-wall projects.