Concrete slab cost per square foot

Cost by thickness

What moves the price

• Base prep. Excavation, hauling, and 4–6 inches of compacted gravel can add $2–$4/sq ft.
• Reinforcement. Wire mesh is cheap; #4 rebar on a grid adds $0.75–$1.50/sq ft.
• Finish. Broom finish is standard. Exposed aggregate, stamping, or saw-cut patterns add $3–$10/sq ft.
• Access. A pump truck runs $800–$1,500 when the truck cannot reach the forms.
• Minimum loads. Most ready-mix suppliers charge a short-load fee below 3–5 yards.

DIY vs. hiring it out

Material for a 10 × 10 ft, 4-inch slab is about $180–$240 in ready-mix. A contractor charges $600–$1,400 installed. The gap pays for forms, base compaction, reinforcement, finishing, and hauling — and for the risk if the pour goes wrong.

DIY makes sense for small pads under 100 sq ft, sheds, and hot tubs, where a two-person crew can place and finish one pour. Above that, the labor and equipment cost of doing it well usually offsets the savings.

Where the money actually goes

Concrete is the most visible line on a slab quote and one of the smallest. A mid-range 400 square foot slab at 4 inches, priced in a market where ready-mix runs $150 a yard, decomposes roughly like this:

The material is roughly a quarter of the bill. That single fact explains most of what follows, including why a quote that looks cheap usually is not, and why doing it yourself saves less than the material percentage suggests.

The cheapest bid usually skips the base

Base preparation is invisible once the concrete is placed, which makes it the first thing a low bid removes. Four inches of compacted gravel, placed in lifts and watered, runs $2 to $4 a square foot. A bid that comes in $2 a square foot under the others is often a bid with no base in it.

Read a slab bid by what it lists, not by the total:

• Excavation depth, and whether spoil is hauled away or left on site
• Gravel thickness, and the compaction method — a plate compactor in lifts, not a rake
• Reinforcement size and spacing, stated as “#4 at 18 inches each way” rather than “rebar included”
• Joint layout and who cuts them, and how soon after the pour
• Cure method — curing compound, plastic, or nothing

A slab poured on a poor base fails from underneath, and no amount of admixture or fibre fixes it.

Finish is the largest discretionary line

Everything above the concrete is optional, which is why finish is where budgets move most.

Stamping carries hidden cost beyond the line item. The mix has to be stiff enough to hold an impression, which means less water and faster setting; the work has to happen in cool weather or early in the day; and it needs a second crew working behind the finishers. That is why a stamped patio can cost more than double a broom-finished one of the same size.

What DIY actually saves, and what it costs instead

Material is about a quarter of an installed price, so doing the work yourself removes most of the bill — and replaces it with forms, base, reinforcement, finishing tools, and the risk of a pour that has to be broken out and redone.

The constraint that decides the question is rarely skill. It is time. Once concrete is in the forms you have a window of roughly an hour to strike, float, and finish before it sets, and that window does not care how experienced you are. Two people can comfortably finish 100 square feet. At 200 square feet the finishing window becomes tight; past that, the crew size has to grow with the slab or the surface is lost. That is the real boundary between a DIY pad and a hired slab, and it sits well below the point where the material cost becomes interesting.

Frequently asked questions

Note: Quantities and prices are estimates for planning. Confirm against the bag yield or quote you are actually buying from.

Last reviewed: October 30, 2026 · Sources: regional ready-mix price surveys; NRMCA; contractor bid data

Related: Concrete calculator · Bags per yard · Curing time · All material calculators