Cost Estimators · Concrete
Concrete Slab Cost Per Sq Ft Calculator
Enter your slab area and instantly estimate concrete slab cost — patio, garage floor, or basement.
Concrete slab quotes often surprise homeowners because the price per sq ft changes significantly with slab thickness, reinforcement, and finish type. A 4-inch broom-finish patio slab costs roughly half of a 6-inch reinforced garage floor. Use this calculator to get a reliable cost range before meeting with concrete contractors.
Enter an area above to see your estimate
Using national average: $5–$12/sq ft
Estimates are based on national averages and are for planning purposes only. Actual costs vary by location, contractor, and material choice.
Example: 500 sq ft concrete slab
Area
500
sq ft
Low Estimate
$2,500
@ $5/sq ft
High Estimate
$6,000
@ $12/sq ft
Based on national average rates of $5–$12/sq ft. Actual costs will vary by location and contractor.
What does a concrete slab cost per square foot?
A basic 4-inch concrete slab with a broom finish costs $5–$8 per sq ft installed. A 6-inch reinforced garage floor runs $7–$12 per sq ft. Decorative or stamped concrete slabs cost $10–$20+ per sq ft. Site prep — grading and gravel sub-base — adds $1–$3/sq ft before the pour. Removal of an existing slab adds another $2–$5/sq ft. For volume-based estimates including cubic yards and bag counts, see our concrete cost per sq ft calculator.
Cost by project size
| Project size | Low estimate | High estimate |
|---|---|---|
| 200 sq ft (small patio) | $1,000 | $2,400 |
| 400 sq ft (standard patio) | $2,000 | $4,800 |
| 600 sq ft (large patio) | $3,000 | $7,200 |
| 800 sq ft (garage floor) | $4,000 | $9,600 |
| 1,200 sq ft (shop / large garage) | $6,000 | $14,400 |
Approximate 2026 US national averages at $5–$12/sq ft installed. Actual costs vary by location, contractor, and project complexity.
What affects concrete cost per square foot?
Slab thickness
A 4-inch slab is standard for patios and walkways. Garages and driveways need 5–6 inches. Each additional inch of thickness adds roughly 25% more concrete volume — and cost. Thicker slabs also require more forming and longer pour times.
Reinforcement type
Wire mesh is standard and adds ~$0.25/sq ft. Rebar on a 12 in grid is recommended for garages and heavy loads — adding ~$1/sq ft. Fibre reinforcement is a mid-range alternative that improves crack resistance without the labour of placing rebar.
Finish type
Broom finish is the cheapest at $5–$8/sq ft. Exposed aggregate adds $2–$4/sq ft. Stamped and coloured concrete adds $8–$15/sq ft to the base price — the largest single variable in slab cost after size.
Site preparation
Grading, excavation, and compacted gravel sub-base adds $1–$3/sq ft before any concrete is poured. Sloped, rocky, or poorly draining sites cost significantly more to prepare. Skipping proper sub-base preparation leads to cracking and settling.
Existing surface removal
Removing an old concrete slab adds $2–$5/sq ft including breaking and disposal. Pavers or gravel removal costs $1–$2/sq ft. Always get quotes that clearly separate demolition and disposal from the new pour cost.
Season & curing conditions
Concrete must be poured and cured in temperatures above 40°F. Cold-weather pouring requires insulated blankets or heated enclosures — adding $0.50–$2/sq ft. Hot, dry conditions require misting and curing compounds to prevent premature drying.
Frequently asked questions
How much does a concrete slab cost per square foot?
A standard 4-inch concrete slab with broom finish costs $5–$8 per sq ft installed. A 6-inch reinforced slab for a garage costs $7–$12/sq ft. Decorative stamped concrete runs $12–$20+/sq ft. For a 500 sq ft patio, expect $2,500–$6,000 all-in.
How thick should a concrete slab be?
Patios and walkways: 4 inches. Residential driveways: 4–5 inches. Garage floors: 4–6 inches. Shop floors with heavy vehicles: 6+ inches. Thicker slabs cost more but resist cracking and load stress significantly better than minimum-thickness pours.
How much concrete do I need for a 10×10 slab?
A 10×10 ft slab (100 sq ft) at 4 inches thick needs approximately 1.23 cubic yards of concrete. At 6 inches, that rises to 1.85 cubic yards. Always add 10% for overpour and waste — order 1.35 and 2.05 cubic yards respectively.
How long does a concrete slab take to cure?
Concrete reaches ~70% strength at 7 days and full design strength (3,000–4,000 PSI) at 28 days. You can walk on it after 24–48 hours. Drive a passenger car after 7 days. Wait the full 28 days before heavy vehicle loads or permanent structure placement.
Do I need a permit for a concrete slab?
Permits are typically required for slabs over 200 sq ft or those that form part of a structure (garage floor, foundation). Freestanding patio slabs often don't require a permit, but requirements vary by municipality. Check with your local building department before pouring.