Concrete Slab Cost (2026): Price per Square Foot by Size

Concrete Slab Cost per Square Foot

HomeGuide's 2026 slab cost guide puts the installed rate for a 4-inch slab at $6 to $8 per square foot. A contractor's price normally includes site prep, the gravel base, forms, reinforcement, the concrete and the crew that places and finishes it, but ask each contractor what their quote leaves out.

The concrete itself is the smaller part. Ready-mix costs $110 to $150 per cubic yard. A cubic yard is 27 cubic feet, and at 4 inches (one third of a foot) it covers 27 ÷ ⅓ = 81 square feet. Divide the yard price by 81 and the concrete alone comes to $1.36 to $1.85 per square foot before waste and short-load fees.

Local quotes can land outside the national range. The main reasons are how close the truck can get to the pour, how much digging and grading the site needs, slab thickness, the type of reinforcement, the finish, and labor and material prices in your region. Ask two or three contractors to quote the same thickness, base and reinforcement so the numbers compare.

Concrete Slab Cost Calculator

Enter the slab size and your ready-mix price. The estimate gives cubic yards, the ready-mix cost with 10% waste, the cost in 80 lb bags, and a contractor price at the 4-inch installed rate.

Concrete Slab Cost by Size

A 12 × 12 ft slab, 4 inches thick, costs about $864 to $1,152 installed, and the 1.78 cubic yards of concrete in it cost $196 to $267. The table gives the concrete at 4 and 6 inches thick, with ready-mix at $110 to $150 per cubic yard and no waste allowance, and the installed price at the 4-inch rate ($6 to $8 per sq ft).

Orders smaller than a full truck (about 10 cubic yards) usually add a short-load fee of $40 to $60 per cubic yard. That matters most for the small sizes: a 10 × 10 slab ordered as 1.5 yd³ pays $60 to $90 in short-load fees on top of $165 to $225 of concrete. For other sizes or thicknesses, the concrete slab calculator gives exact yardage with a waste allowance.

Where the Money Goes: Full Cost Breakdown

Of the $6 to $8 per sq ft installed rate, the concrete accounts for $1.36 to $1.85 per sq ft before waste and short-load fees. The rest pays for the work and materials below, plus the contractor's insurance, equipment, travel and margin. Knowing the parts makes quotes easier to compare.

• Site prep: removing sod and topsoil, digging to depth, grading so water drains away, and compacting the subgrade. Sloped or soft ground takes more of it.
• Forms: lumber or steel edge forms staked to line and grade before the pour and stripped afterward.
• Base: a compacted gravel layer under the slab, and a vapor barrier under floors inside a building.
• Reinforcement: welded wire mesh, rebar or fiber in the mix. Rebar on a grid takes more material and labor than mesh; see the rebar spacing guide.
• Concrete: ready-mix by the cubic yard, plus the short-load fee on small orders.
• Placing and finishing: the crew that places, screeds, floats and edges the slab, cuts control joints, and applies a broom or trowel finish.
• Curing: keeping the slab moist or covered, or spraying a curing compound, for the first days after the pour. Timing by temperature is in the concrete cure time chart.
• Sealing: a sealer applied after the slab cures. Common on stamped and decorative work, optional on plain broom finish.

Concrete Slab Cost by Project Type

At the 4-inch installed rate, a 12 × 16 patio costs about $1,152 to $1,536 and a 10 × 12 shed base about $720 to $960. The sizes below are typical examples; the figures apply only to 4-inch slabs.

Costs Not in the Per-Square-Foot Price

A per-square-foot rate assumes a level, open site the truck can reach. These items are quoted separately.

• Short-load fee: $40 to $60 per cubic yard on orders under a full truck, so it applies to most residential slabs. Work out your exact yardage before calling suppliers.
• Pumping: needed when the truck's chute cannot reach the pour, as with most backyards and basements. Pump companies charge by the hour or by the job, usually with a minimum.
• Demolition: breaking out and hauling away an old slab. Thicker and rebar-reinforced slabs take longer to remove.
• Permits: many towns require one for driveways, garage floors and structural slabs, and some inspect the forms and base before the pour. Your building department sets the fee.
• Grading and poor soil: fill, extra compaction, drainage work, or digging out soft soil and replacing it with gravel.
• Access: tight sites mean concrete buggies, a pump or extra crew time, and sometimes removing a fence section.

DIY vs. Professional: Real Cost Comparison

For a 20 × 20 slab, 4 inches thick, the concrete for a DIY pour costs $605 to $825 as ready-mix plus a $220 to $330 short-load fee. A contractor charges about $2,400 to $3,200 for the finished slab.

The bag count is 400 sq ft × 4/12 ft = 133.3 cu ft, plus 10% waste = 146.7 cu ft, ÷ 0.60 cu ft per 80 lb bag = 245 bags. At this size bags cost more than ready-mix, and 245 bags have to be mixed and placed before the first batches start to set. The bags to yards calculator shows where the crossover falls for your project.

A DIY pour needs a screed board, bull float, hand floats, edger, groover, broom and wheelbarrows, a plate compactor for the base, and for a smooth finish a power trowel. The labor is the harder part: a 20 × 20 slab needs three or four people working without a break from the time the truck starts unloading, and the finishing window shrinks in heat, sun and wind. A badly finished slab can only be fixed by breaking it out.

Small shed pads and equipment pads where looks do not matter are reasonable DIY jobs. The common concrete mistakes guide covers what goes wrong most often.

Best Time to Pour

Mild, dry weather is best for pouring a slab, which in most of the US means spring and fall. Contractors are busiest in summer, so a spring or fall job is often easier to schedule.

Cold weather slows curing and calls for insulated blankets, heated enclosures or accelerating admixtures. Hot, dry or windy weather speeds setting and calls for early starts and wet curing. Both add cost. The concrete cure time chart gives temperatures and curing times.

Ready-Mix Concrete Pricing (2026)

Ready-mix concrete costs $110 to $150 per cubic yard for a standard 3,000 to 4,000 psi mix. A full truck holds about 10 cubic yards, and smaller orders add a short-load fee of $40 to $60 per cubic yard. Whether delivery is included in the yard price varies by supplier.

When you call a supplier, ask whether the price includes delivery and how far, how many minutes of unloading time are free, and what they charge for waiting, extra mileage, Saturday delivery and washout.

Work out how many cubic yards you need with the slab calculator, or compare bagged concrete with the bags to yards calculator.

Frequently Asked Questions