Concrete Slab Cost Calculator & Price Guide

A concrete slab is a flat, poured pad used for garage floors, shed bases, patios, parking areas, and the foundation of a house. Slab price comes down to three things: how much area it covers, how thick it is, and what is added to it, such as reinforcing steel or a decorative finish.

This guide focuses on the slab itself. For ready-mix prices by the yard or bag, see the general concrete pricing guide. For driveways, see the concrete driveway guide. Figures below carry a check date of Oct 11, 2026.

Thickness changes the amount of concrete, and the table shows how the per-square-foot rate moves with it. Thin slabs of two to four inches tend to carry the same rate in this source, and the price climbs once a slab gets thicker.

Heavier loads call for thicker slabs. A slab that supports vehicles or a building needs more depth than one that carries foot traffic. A contractor or engineer should confirm the thickness for your use rather than choosing the cheapest option.

The table lists typical totals for common slab projects. These are single reported figures, so treat them as reference points and not quotes.

A garage slab or a foundation costs more than a small pad because of size, thicker pours, and added reinforcement. Foundation slabs often involve engineering and inspections that a simple parking pad does not.

Concrete is sold by the cubic yard. To estimate volume, multiply length, width, and thickness (in feet), then divide by 27. Order a little extra to cover uneven ground, because running short mid-pour leaves a seam.

Material is only part of the bill. Labor, forming, finishing, and site preparation often add more than the concrete does, which is why the per-square-foot rates above run higher than raw material prices alone.

Most slabs include some form of reinforcement, usually steel rebar or wire mesh, to help control cracking. Surface treatments are optional and are priced per square foot on top of the base slab.

Patios are a slab project of their own. A plain gray surface sits near the bottom of the range, while stained or stamped finishes cost more because they need extra labor and materials.

• Area and thickness. More square feet and more depth mean more concrete.
• Ground conditions. Soft, sloped, or poorly draining soil needs excavation, grading, or a thicker gravel base.
• Reinforcement. Rebar and mesh add material and labor.
• Finish. A broom finish is the plainest. Staining, coloring, and stamping cost extra.
• Access. If a concrete truck cannot reach the site, crews may need pumps or wheelbarrows, which adds labor.
• Permits and inspections. Slabs for structures usually require a permit, and foundation slabs often need an inspection before the pour.
• Removal. Breaking out an old slab and hauling it away is a separate charge.

Sources describe slabs differently. One may report a general rate for foundations and reviews, while another reports patio work, which skews toward decorative finishes.

Neither range is wrong. They describe different jobs, so match the source to your project type before relying on a number.

A thinner slab costs less and works for light uses such as walkways or a small patio. A thicker slab handles vehicles, equipment, and structural loads, and is the safer choice for garages and foundations. Choosing a thin slab for a heavy use risks cracking and early replacement, so the cheaper option can end up costing more. Reinforcement is a separate decision that you can price on its own.

The sources used here price new slabs rather than repairs, so no repair figure is listed. Small cracks and surface damage can often be patched or sealed. Slabs that have settled, heaved, or cracked through usually point to a ground or drainage problem, and a contractor may recommend replacement. Fixing the cause before repouring helps keep the new slab from failing the same way.

Pouring a small pad for a shed is within reach for some homeowners, but concrete sets on a clock. Mistakes in forming, leveling, or finishing are hard to undo once it hardens. Large slabs, garage floors, and foundations are better left to a professional crew, and structural slabs may require engineered plans and a licensed contractor under local code.

• Does the quote include excavation, base material, forms, and reinforcement?
• What slab thickness is quoted, and is it right for the load?
• Is finishing, sealing, and cleanup included?
• Who pulls the permit and schedules inspections?
• How long should the slab cure before it takes weight?