Planning a new patio, driveway or garage floor? The price of a concrete slab depends on size, thickness, reinforcement, site prep and finish. This guide gives you 2026 installed prices per square foot from major US cost guides, the right thickness for each use, a free calculator for cubic yards and cost, and the engineering tips that make a slab last for decades.
Quick answer: a basic broom-finished slab usually costs about $4 – $8 per sq ft installed for a 4-inch patio, and about $6 – $10+ per sq ft for a thicker driveway or garage slab. Stamped or decorative concrete costs about $8 – $15 per sq ft or more.
Concrete slab cost per square foot (2026)
| Project | Usual thickness | Installed cost per sq ft | Example size and total |
|---|---|---|---|
| Patio / walkway | 4 in | $4 – $8 | 20 × 20 ft (400 sq ft): about $1,600 – $3,200 (more with extra prep) |
| Driveway | 5 – 6 in | $6 – $10 | 12 × 40 ft (480 sq ft): about $2,900 – $4,800 |
| Garage floor | 4 – 6 in | About $6 – $14 (wide range by region and footings) | 24 × 24 ft (576 sq ft): about $3,500 – $8,000; much more if footings/foundation walls are included |
| Stamped / colored decorative | 4 in | $8 – $15+ | 400 sq ft: about $3,200 – $6,000 |
Free concrete slab calculator
How to calculate concrete by hand
Cubic yards = Length (ft) × Width (ft) × Thickness (in) ÷ 12 ÷ 27
Example: 20 × 20 ft patio, 4 in thick: 20 × 20 × 4 ÷ 12 = 133.3 cu ft. Divide by 27 = 4.94 cu yd. Add about 10% for uneven base and spillage: order about 5.5 cu yd.
Handy rule: one cubic yard covers about 81 sq ft at 4 inches, or about 54 sq ft at 6 inches.
What is included in the price
- Ready-mix concrete: roughly $125 – $165 per cubic yard delivered in many markets (short-load fees for small orders).
- Labor for placing and finishing: often the largest part of the price.
- Site prep: removing old concrete, excavation, gravel base and compaction. This can add about $1 – $3 per sq ft.
- Reinforcement: wire mesh or rebar, plus forms.
- Finish: broom finish is cheapest; exposed aggregate, color and stamping cost more.
- Permits (driveways and garages often need one) and pump truck if access is hard.
Engineering tips for a slab that lasts
1. Base and compaction
Most slab cracks start under the slab. Remove topsoil and organic material, then place and compact a granular base (often 4 inches of crushed stone). Soft spots under the slab become cracks later. Read more on soil compaction.
2. Thickness
4 inches for patios and walkways. 5–6 inches for driveways, especially for trucks, RVs or soft soils. Adding one inch costs little compared with the extra life it gives.
3. Control joints
Concrete shrinks as it dries, so it will crack. Control joints decide where. A common rule is to space joints at about 2 to 3 times the slab thickness in feet (a 4-inch slab: every 8–12 ft), cut to about one quarter of the thickness. Keep panels close to square.
4. Mix and water
Ask for a mix suited to your climate (air-entrained concrete for freeze–thaw areas). Do not let the crew add extra water to make it easier to place. Extra water makes concrete weaker and more likely to crack and scale. The science is explained in our water-cement ratio guide.
5. Curing
Keep the slab moist for about 7 days (wet curing, curing blankets or a curing compound), and keep cars off for about a week or as your contractor advises. See curing of concrete.
Frequently asked questions
Is it cheaper to pour concrete yourself?
For small pads under about 1 cubic yard, bagged concrete can save money. For bigger slabs, finishing is hard work with a short time window, and mistakes are permanent, so hiring a crew is usually worth it.
How much does a 24 × 24 garage slab cost?
576 sq ft at about $6 – $14 per sq ft is roughly $3,500 – $8,000 for the slab. Prices go well above that when thickened edges, footings or foundation walls are included.
Do I need rebar in a patio slab?
Not always, but wire mesh or light rebar helps hold cracks tight. Driveways and garage floors usually benefit from reinforcement. Good base prep and joints matter more.
Related guides
- Concrete vs Asphalt Driveway: Cost, Life & Maintenance
- Slab Reinforcement Details
- Why Concrete Cracks on Site
Price sources: 2026 data from This Old House, Inch Calculator and HomeStars. Ranges are national estimates; always get local quotes.
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