How Much Does a Concrete Slab Cost?
A plain 4-inch concrete slab typically costs about $4 to $8 per square foot installed in 2026, according to national cost guides. A 10×10 shed pad lands around $400–$800 and a 20×20 patio or garage slab around $1,600–$3,200 before extras like stamping or rebar.
Concrete slab cost by size
| Slab | Area | Typical installed cost ($4–$8/sq ft) |
|---|---|---|
| 10×10 shed pad | 100 sq ft | $400–$800 |
| 12×12 patio | 144 sq ft | $576–$1,152 |
| 12×20 patio | 240 sq ft | $960–$1,920 |
| 20×20 patio or 2-car pad | 400 sq ft | $1,600–$3,200 |
| 24×24 garage slab | 576 sq ft | $2,304–$4,608 |
| 30×30 slab | 900 sq ft | $3,600–$7,200 |
Small slabs often cost more per square foot because the contractor's setup time, forms and minimum delivery charges are spread over less area.
What's included — and what costs extra
- Base price covers forming, a compacted gravel base, the concrete itself, finishing and control joints.
- Reinforcement: This Old House lists wire mesh at roughly $0.35 per sq ft and rebar at about $2–$3 per sq ft.
- Decorative finishes: stamping commonly adds around $10–$14 per sq ft, and coloring or staining several dollars more.
- Thickness: going from 4 to 6 inches adds 50% more concrete; driveways and slabs carrying vehicles are often 5–6 inches.
- Site work: excavation, removing an old slab, poor access for the truck or a pump add to the bill.
Material cost if you do it yourself
Ready-mix concrete is commonly quoted around $125–$175 per cubic yard delivered, and one cubic yard covers 81 sq ft at 4 inches thick. Bagged concrete makes sense for small pads: a 10×10 slab 4 inches thick needs 62 bags of 80 lb mix with 10% extra. Use the concrete calculator to get the exact volume for your slab, then enter your local bag or yard price to see the material cost.
How to save
- Combine projects (patio plus walkway) so the truck and crew visit once.
- Prepare and compact the base yourself if your contractor allows it.
- Choose a broom finish instead of stamping; add color with a stain later if you want.
Sources
Prices vary widely by region, season and contractor. Use these ranges to plan, then get at least three written quotes.