Concrete slab cost

A slab is priced by the square foot, and the range published for it is wide because a 4-inch patio slab and a structural foundation slab are the same words for very different work. The figures below are per square foot where the guide gives one, and as a project total where it does not.

What the guides publish

Homewyse$10.33 – $12.99 per sq ft

May 2026 · National average basis for a cement slab installed.

Bob Vila$5,200 – $21,000 total

Updated Jan 16, 2024 · typical $9,100 · Foundation figures citing Angi: $5–$37 per sq ft across all foundation types; slab-on-grade $4–$14 per sq ft.

What the parts cost

Slab-on-grade$4 – $14 per sq ft

Bob Vila. The ordinary case for a garage, shed or patio slab.

Stem wall foundation$20 – $37 per sq ft

Bob Vila. More concrete and more reinforcement than slab-on-grade.

Concrete slab as a foundation$5,200 – $21,000 total

Bob Vila, by structure type.

Garage slab$2,000 – $7,000 total

Bob Vila

Footings$6.50 per sq ft

Bob Vila gives an average of $6.50 per sq ft; not every slab needs them.

What moves the price

Thickness and reinforcement: Four inches with mesh is the common patio and shed slab. A slab carrying a structure is thicker, has thickened edges and rebar, and the concrete volume rises with it.
Ground preparation: Excavation, base stone, compaction and a vapour barrier are separate from the pour, and on a sloped or soft site they can exceed it.
Access for the truck: A truck that can back to the forms is the cheap case; pumping or barrowing adds hours.
Finish: A broom finish is standard. Stamping, colouring or polishing are priced separately and can multiply the surface cost.

Questions

How much does a concrete slab cost per square foot?

Homewyse publishes $10.33–$12.99 per square foot installed (May 2026). Bob Vila gives $4–$14 per square foot for slab-on-grade and $20–$37 for a stem wall foundation (January 2024, citing Angi).

How much concrete will I actually need?

Volume, not area, is what you order: length by width by thickness, in cubic yards, plus a waste allowance. The concrete calculator does that and converts it to bags or truck yards.

These are the ranges other people publish, gathered on 2026-09-06 — not our estimate, and not a quote. Every guide is linked above with the date it prints. For the quantity rather than the price: Concrete calculator, Cubic yard calculator. See every cost page.