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SlabCosts
Prices updated January 2026

12×24 Concrete Slab Cost

A 12×24 slab covers 288 square feet. Here's the concrete, bags and cost for 2026 — a common size for a single-car driveway.

Concrete (4", waste in)

3.91 yd³

176 × 80 lb bags

Materials (ready-mix)

$549 – $918

delivered, 4" slab

Installed by a pro

$1,584 – $3,456

4" slab, national average

12×24 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

$1,584 – $3,456

288 sq ft · 3.91 yd³ concrete

Bags of concrete needed (rounded up)

176

80 lb

235

60 lb

282

50 lb

352

40 lb

Ready-mix (delivered)
$549 – $918
Bagged mix (80 lb, DIY)
$968 – $1,584
Installed by a pro
$1,584 – $3,456

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

Installed $1,584 – $3,456

12×24 slab cost by thickness

Thickness Concrete 80 lb bags Ready-mix Installed
4" 3.91 yd³ 176 $549 – $918 $1,584 – $3,456
5" 4.89 yd³ 220 $671 – $1,104 $1,800 – $3,672
6" 5.87 yd³ 264 $793 – $1,290 $2,016 – $3,888

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

4.09 yd³

4" compacted base under the slab

≈ $123 – $266

Open calculator
Rebar

21 sticks

#4 bar, 18" grid (26 bars)

≈ $147 – $273

Open calculator
Bedding sand

0.89 yd³

~1" leveling layer

≈ $25 – $52

Open calculator

12×24 concrete slab: what to expect

A 12×24 slab covers 288 square feet. At the standard 4" thickness it takes about 3.91 cubic yards of concrete once you allow 10% for waste, which is roughly 176 × 80 lb bags if you mix by hand. Stepping up to 6" — sensible if it'll carry a vehicle — raises that to about 5.87 cubic yards.

Budget around $1,584 – $3,456 to have a 4" slab this size poured and finished by a contractor, or roughly $549 – $918 in ready-mix if you're doing the labor yourself. On top of the concrete you'll need about 4.09 yd³ of gravel base and 21 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
10×20 2.72 yd³ 123 $1,100 – $2,400
15×15 3.06 yd³ 138 $1,238 – $2,700
16×16 3.48 yd³ 157 $1,408 – $3,072
16×20 4.35 yd³ 196 $1,760 – $3,840
18×20 4.89 yd³ 220 $1,980 – $4,320
20×20 5.43 yd³ 245 $2,200 – $4,800

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 12×24 concrete slab cost?
A 12×24 slab (288 sq ft) costs about $1,584 – $3,456 installed at 4" thick in 2026, or $2,016 – $3,888 at 6". DIY in materials, the ready-mix runs about $549 – $918 at 4".
How many yards of concrete for a 12×24 slab?
At 4" thick a 12×24 slab needs about 3.91 cubic yards including 10% waste (3.56 yd³ net). At 6" it needs about 5.87 cubic yards.
How many bags of concrete for a 12×24 slab?
At 4" you'd need roughly 176 × 80 lb bags, 235 × 60 lb bags or 352 × 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 12×24 slab need?
Plan on about 4.09 cubic yards of compacted gravel base and roughly 21 sticks of #4 rebar on an 18" grid. The "You'll also need" cards size these for you.