Slab Cost Calculator

Prices updated July 2026 · all 50 states

Your slab

Your estimate

Professionally installed
Per square foot
Concrete needed
Volume (+10% waste)
Ready-mix delivered
80 lb bags (DIY)

How much does a concrete slab cost in 2026?

A professionally installed concrete slab costs $6 to $12 per square foot for a standard 4-inch broom-finished pour in mid-2026, with the national average landing around $8.50. A typical 12×12 ft patio slab runs $1,150–$1,600 installed, while a 20×24 ft two-car garage slab costs $4,800–$7,000. Ready-mix concrete itself averages $150–$185 per cubic yard delivered, so material is roughly a third of the installed price — labor, forming, sub-base prep, and finishing make up the rest.

📷 Your photo here — a slab being poured or finished (original photos outrank stock)

Concrete slab cost by size

Slab sizeSq ftThicknessInstalled cost (2026)
8 × 8 (hot tub pad)644″$550 – $800
10 × 101004″$800 – $1,200
12 × 12 (patio)1444″$1,150 – $1,600
10 × 20 (shed base)2004″$1,500 – $2,200
12 × 40 (driveway)4805″$4,300 – $6,200
20 × 24 (2-car garage)4806″$4,800 – $7,000
24 × 30 (workshop)7206″$7,200 – $10,500

Where the money goes

WHAT YOU PAY FOR IN AN INSTALLED SLAB LABOR & CREW · 40% CONCRETE · 32% PREP · 18% 10% LABOR & CREW — forming, pouring, screeding, curing supervision CONCRETE — ready-mix delivered at $150–$185 per cubic yard (July 2026 avg) PREP — excavation, grading, gravel sub-base, wire mesh or rebar FINISH — broom/trowel texture, control joints, cure & seal (10%) Source: ProjectCosted contractor pricing survey, July 2026
Typical cost breakdown of a professionally installed 4″ slab (national average, July 2026).

6 factors that change your price

1. Thickness. Moving from 4″ to 6″ means 50% more concrete and stiffer forming — expect 20–30% more on the installed price. Use 4″ for patios and walkways, 5–6″ for anything a vehicle sits on.

2. Site prep. A sloped or soft site needs excavation, grading, and a compacted gravel base — adding $1–$3 per sq ft.

3. Reinforcement. Wire mesh (~$0.50/sq ft) is standard for patios; a rebar grid (~$1.25/sq ft) is the right call for driveways and garages.

4. Finish. Broom finish is baseline. Exposed aggregate adds $3–5/sq ft, stamping adds $5–10/sq ft.

5. Your state. Labor in California, New York, and Hawaii runs 20–38% above the national average; much of the South runs 10–15% below. The calculator above adjusts automatically.

6. Truck access. If the mixer can’t get within chute distance of the pour, concrete pumping adds $150–$300.

DIY vs hiring a contractor

Material alone is roughly 30–50% of the installed price, so DIY can genuinely halve the cost — but only for small, simple slabs. A slab under about 80 sq ft is a realistic weekend project for two people using bagged concrete (about 45 bags per cubic yard at ~$5.40 per 80 lb bag). Beyond that, order ready-mix — but note most suppliers charge a short-load fee of $75–$150 on orders under 4–5 yards.

Driveways and garage slabs are usually worth hiring out: they need correct sub-base compaction, control joints cut at the right spacing, and a continuous pour that’s hard to manage solo. A failed slab costs more to demolish and re-pour than the original quote.

How this calculator works

Volume = length × width × thickness converted to cubic yards, plus a 10% industry-standard waste allowance. Material prices reflect national ready-mix and bagged-concrete averages surveyed July 2026; installed prices combine materials with regional labor rates, and your state selection applies a local cost index. Estimates are for planning — confirm with local quotes.

Frequently asked questions

How much does a 12×12 concrete slab cost?
$1,150–$1,600 installed for a 4-inch broom-finished slab in 2026, or roughly $475 in bagged material if you pour it yourself.
How many 80 lb bags equal one cubic yard?
About 45 bags — each yields roughly 0.60 cubic feet, and a yard is 27 cubic feet.
How thick should my slab be?
4 inches for patios, walkways, and sheds; 5–6 inches for driveways and garages; 6–8 inches for heavy equipment.
How long until I can use the slab?
Foot traffic in 24–48 hours, vehicles after 7 days, full strength at 28 days.
Does the price include removing an old slab?
No — demolition and haul-away adds $2–$6 per square foot.

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