How Much Does a 12x12 Concrete Slab Cost?
A 12x12 concrete slab costs about 900 to 1,700 dollars installed in 2026, or roughly 6 to 12 dollars per square foot for a standard 4 inch pour with a broom finish. Pouring it yourself drops the bill under 1,000 dollars in materials. Here is what drives that price, the volume and bag math, and a calculator that sizes the job in seconds.
Key takeaways
- A 12x12 slab covers 144 square feet and costs about 900 to 1,700 dollars installed in 2026, near 8 dollars per square foot on average.
- At 4 inches thick it needs about 1.8 cubic yards of concrete, or roughly 80 bags of 80 lb mix.
- Going from 4 to 6 inches uses about 50% more concrete, pushing material cost up sharply.
- DIY materials run under 1,000 dollars; the rest of a pro quote is labor, reinforcement and finish.
- Northeast and California markets add 20 to 45% to the national average.
What a 12x12 concrete slab costs installed in 2026
A 12x12 slab covers 144 square feet, one of the most common sizes for sheds, patios and small pads. Installed by a contractor with a standard 4 inch pour and a broom finish, expect about 900 to 1,700 dollars in most US markets in 2026.
That works out to roughly 6 to 12 dollars per square foot, with the national average sitting near 8 dollars. The spread comes down to thickness, reinforcement, finish and where you live.
| Scenario | Price per sq ft | 12x12 total |
|---|---|---|
| Basic 4 in, broom finish | $6 to $8 | $865 to $1,150 |
| 4 in with mesh + vapor barrier | $9 to $10 | $1,300 to $1,440 |
| 6 in, rebar, heavy duty | $10 to $13 | $1,440 to $1,870 |
| Stamped or stained finish | $12 to $18+ | $1,730 to $2,600+ |
To pin down your own number, enter the dimensions in the concrete slab calculator and it returns yards, bags and an estimated cost.
Material cost: concrete, ready-mix vs bags
A 4 inch 12x12 slab holds about 1.8 cubic yards of concrete (12 x 12 x 0.333 = 48 cubic feet, divided by 27). Ready-mix delivered runs roughly 135 to 185 dollars per cubic yard in 2026, so the concrete alone is about 240 to 330 dollars before any short-load fee.
Suppliers add a short-load fee, often 40 to 60 dollars per yard, when you order well under a full truck of about 10 yards. On a 1.8 yard pour that fee matters, so ask for the all-in delivered price.
Bagging it instead means about 80 bags of 80 lb mix (48 cubic feet divided by 0.6 per bag), close to 400 dollars at the store. That is a lot of mixing, which is why a pour this size is right on the line between bags and ready-mix.
Labor and reinforcement add-ons
Labor is usually the biggest line on a pro quote, around 3 to 5 dollars per square foot for forming, pouring and finishing a standard slab. On 144 square feet that is roughly 430 to 720 dollars, more in high-cost metros.
Reinforcement is a smaller add. Welded wire mesh, the usual choice for a 4 inch slab, costs only about 0.20 to 0.30 dollars per square foot, so 29 to 43 dollars in material. A rebar grid runs 2 to 3 dollars per square foot installed and is worth it only when the slab carries vehicles or heavy loads.
If your pad needs to bear real weight you are likely going to 6 inches and footings; the concrete footing calculator sizes the thickened edge separately from the slab.
How thickness changes the 12x12 price
Thickness is the single biggest lever on material cost. Four inches is standard for patios, walkways and shed floors. Bump to 6 inches for driveways or anything bearing vehicles, and you use about 50% more concrete.
A 4 inch 12x12 needs about 1.8 cubic yards; a 6 inch version needs about 2.7. That extra yard of ready-mix plus rebar is the main reason heavy-duty pads land at the top of the range. If you are unsure which depth fits, our guide on how thick a concrete slab should be walks through the use cases.
| Thickness | Cubic yards (12x12) | 80 lb bags |
|---|---|---|
| 4 in | 1.8 | ~80 |
| 5 in | 2.2 | ~100 |
| 6 in | 2.7 | ~120 |
Region, site prep and other cost factors
Where you live can swing the bill 20 to 45%. The Northeast and California run well above the national average, while the South and Midwest sit at or below it. Always get two or three local written bids on the same spec.
Site prep is the hidden variable. A flat, compacted, well-drained pad pours cheap. Sloped ground, soft subgrade, removal of an old slab, or a long wheelbarrow run from the truck all add labor and concrete. A soft base quietly swallows extra yards, so a waste allowance of 5 to 10% is standard.
DIY vs hiring a pro
Doing it yourself can bring a 12x12 in under 1,000 dollars in materials: concrete, mesh, form lumber and gravel. The catch is mixing 80 bags or wrangling a ready-mix delivery, plus screeding and finishing 144 square feet before it sets.
A pro charges more but handles forms, grade, finish and timing, which is where slabs go wrong. For a structural pad or anything you will build on, the labor premium usually pays for itself.
Either way, start with the numbers. Drop your length, width and thickness into the concrete slab calculator to get the cubic yards, bag counts and a cost estimate before you call a single supplier.
Frequently asked questions
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References
- Concrete (Wikipedia)
- QUIKRETE Concrete Mix yield (spec sheet)
- ACI 332: Residential concrete code
- Sakrete: Estimating bagged concrete jobs