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SlabCosts
Prices updated January 2026

12×12 Concrete Slab Cost

A 12×12 slab covers 144 square feet. Here's the concrete, bags and cost for 2026 — a common size for a patio.

Concrete (4", waste in)

1.96 yd³

88 × 80 lb bags

Materials (ready-mix)

$305 – $547

delivered, 4" slab

Installed by a pro

$792 – $1,728

4" slab, national average

12×12 slab cost calculator

Adjust thickness, waste or region — the cost updates live.

Waste & region

Order extra for spillage & uneven subgrade. 10% is typical.

Installed cost estimate

$792 – $1,728

144 sq ft · 1.96 yd³ concrete

Bags of concrete needed (rounded up)

88

80 lb

118

60 lb

141

50 lb

176

40 lb

Ready-mix (delivered)
$305 – $547
Bagged mix (80 lb, DIY)
$490 – $801
Installed by a pro
$792 – $1,728

Estimate only — not a quote. Bag counts are rounded up and include a 10% waste allowance.

Installed $792 – $1,728

12×12 slab cost by thickness

Thickness Concrete 80 lb bags Ready-mix Installed
4" 1.96 yd³ 88 $305 – $547 $792 – $1,728
5" 2.44 yd³ 110 $366 – $639 $900 – $1,836
6" 2.93 yd³ 132 $427 – $732 $1,008 – $1,944

Includes a 10% waste allowance; bag counts rounded up. National US averages, January 2026.

You'll also need

Sized for this exact slab — tap any item to open its calculator with your measurements already filled in.

Gravel base

2.04 yd³

4" compacted base under the slab

≈ $61 – $133

Open calculator
Rebar

11 sticks

#4 bar, 18" grid (18 bars)

≈ $77 – $143

Open calculator
Bedding sand

0.44 yd³

~1" leveling layer

≈ $12 – $26

Open calculator

12×12 concrete slab: what to expect

A 12×12 slab covers 144 square feet. At the standard 4" thickness it takes about 1.96 cubic yards of concrete once you allow 10% for waste, which is roughly 88 × 80 lb bags if you mix by hand. Stepping up to 6" — sensible if it'll carry a vehicle — raises that to about 2.93 cubic yards.

Budget around $792 – $1,728 to have a 4" slab this size poured and finished by a contractor, or roughly $305 – $547 in ready-mix if you're doing the labor yourself. On top of the concrete you'll need about 2.04 yd³ of gravel base and 11 sticks of rebar.

Compare nearby sizes

Planning something bigger or smaller? Jump straight to the cost for a nearby size.

Size Concrete (4") 80 lb bags Installed cost
8×10 1.09 yd³ 49 $440 – $960
10×10 1.36 yd³ 62 $550 – $1,200
10×12 1.63 yd³ 74 $660 – $1,440
12×16 2.61 yd³ 118 $1,056 – $2,304
14×14 2.66 yd³ 120 $1,078 – $2,352
10×20 2.72 yd³ 123 $1,100 – $2,400

See all common slab sizes →

Prices updated January 2026 National US averages · reviewed quarterly

Volumes use standard bag yields and a 10% waste allowance; costs are national US averages that vary by region, mix and finish. See our methodology for exactly how each figure is worked out, or check the reference sources:

Slab cost by project

Concrete Slab Cost Cost per sq ft + calculator Garage Slab Cost Typical 20×20 / 24×24 Driveway Slab Cost Concrete vs asphalt Patio Slab Cost 10×10 to 20×20 Shed Base Cost Small pads

Frequently asked questions

How much does a 12×12 concrete slab cost?
A 12×12 slab (144 sq ft) costs about $792 – $1,728 installed at 4" thick in 2026, or $1,008 – $1,944 at 6". DIY in materials, the ready-mix runs about $305 – $547 at 4".
How many yards of concrete for a 12×12 slab?
At 4" thick a 12×12 slab needs about 1.96 cubic yards including 10% waste (1.78 yd³ net). At 6" it needs about 2.93 cubic yards.
How many bags of concrete for a 12×12 slab?
At 4" you'd need roughly 88 × 80 lb bags, 118 × 60 lb bags or 176 × 40 lb bags. That's a lot of mixing — past about a cubic yard, ready-mix is usually cheaper and easier.
What base and rebar does a 12×12 slab need?
Plan on about 2.04 cubic yards of compacted gravel base and roughly 11 sticks of #4 rebar on an 18" grid. The "You'll also need" cards size these for you.