Concrete Slab Cost Calculator

Estimate the installed cost of a concrete patio, driveway, garage floor, or shed pad. Enter the size, thickness, finish, and reinforcement to see a realistic range.

Updated November 2026 · U.S. pricing

Your slab

Estimates assume standard site prep, forms, and typical access. Rock, poor drainage, and steep slopes cost more.

Enter your slab dimensions to see an estimate.
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How this concrete cost estimate works

The calculator starts with a typical installed cost per square foot for the chosen thickness, then adds the selected finish and reinforcement. Removal of an old slab is calculated separately. The range reflects differences in site prep, access, and local labor rates.

Installed costs include excavation and grading of a standard base, compacted gravel, forms, concrete, finishing, and cleanup. They do not include retaining walls, drainage corrections, or permit fees.

Concrete slab cost per square foot

ThicknessTypical useInstalled per sq ft
4 inPatios, walkways, shed pads$6–$10
5 inLight driveways, heavy foot traffic$7–$12
6 inDriveways, garage floors, heavy loads$9–$15

Base range includes standard prep, gravel base, forms, concrete, broom finish, and labor.

Finish and reinforcement add-ons

OptionAdded cost per sq ftNotes
Broom finishIncludedStandard slip-resistant surface
Stamped concrete+$4–$8Patterns, color, and sealer
Exposed aggregate+$3–$6Textured pebble surface
Wire mesh+$0.50–$1.50Common for patios and shed pads
Rebar+$1–$2.50Typical for driveways and structural slabs
Old slab removal+$2–$5Includes breaking, hauling, and disposal

What a 20×20 slab costs

A 400-square-foot, 4-inch broom-finish slab with wire mesh typically costs $2,600–$4,600 installed at average U.S. rates. Upgrading to stamped concrete adds roughly $1,600–$3,200, and a 6-inch driveway slab at the same size runs about $4,200–$7,000 before reinforcement.

What changes the price

Site prep

Flat, accessible ground is cheap to prep. Slopes, soft soil, tree roots, and poor drainage require excavation, fill, or a retaining wall, all of which add cost quickly.

Access

Concrete trucks need to get close. A long carry from the street, a narrow gate, or a backyard with no access adds wheelbarrow labor and can push the price up 10–25%.

Climate and code

Cold climates require deeper footings for frost, and some jurisdictions require thicker slabs or specific reinforcement for driveways. Check local requirements before comparing quotes.

Finishing

Broom finish is the cheapest and most common. Stamped and exposed aggregate add material, labor, and sealing, and they cost more to repair later.

Concrete driveways and structural slabs usually require a permit. Patios and shed pads may not, but rules vary by municipality. Confirm before work starts, and ask who is responsible for the permit.

Concrete slab FAQ

How much does a 20×20 concrete slab cost?

About $2,400–$4,600 for a 4-inch broom-finish slab at typical U.S. rates, including wire mesh in most quotes. Stamped finishes and 6-inch thickness push the total higher.

How thick should a concrete slab be?

Four inches is typical for patios, walkways, and shed pads. Driveways and garage floors usually need 5–6 inches, and local code or frost depth may require more. Ask your contractor what is specified for your use case.

Does a concrete slab need rebar?

Driveways, garage floors, and slabs carrying heavy loads typically use rebar. Patios and shed pads often use wire mesh, which is cheaper. The right choice depends on soil, load, and local practice.

How much does stamped concrete add?

Stamped concrete usually adds $4–$8 per square foot, covering the pattern, color, and sealer. Repairs are harder to blend than broom finish, so factor in long-term maintenance.