What a slab should cost installed, by finish — with material and base shown separately so an incomplete quote is obvious.
Concrete Slab Cost Calculator
Inputs
Standard is 4 in compacted. Set to 0 if the base already exists.
Results
Estimated installed cost
$3,456 – $5,760
area × $6–$10/ft² installed; material = yd³ × $/yd³
Calculated with BuildCalculators.com
A concrete slab quote is mostly labour. The concrete itself is typically 25–35% of the total, which is why negotiating on mix price barely moves the number and why two quotes for the same slab can differ by thousands.
This calculator splits the material from the installed price so you can see the ratio. If a quote is close to the material cost alone, something is missing from it.
V = length × width × (thickness(in) ÷ 12) ÷ 27order = V × 1.10 (10% waste)order yd³ × $/yd³, plus short-load fee under 4 yd³area × (base(in) ÷ 12) ÷ 27 × 1.2 compaction × $45/yd³area × $/ft² by finishA broom finish is one pass with a broom after floating. Stamped concrete needs release agent, mats, colour and a sealer, and takes several times as long. That is why the same slab runs $6–$10 per square foot broomed and $12–$20 stamped — the concrete underneath is identical.
Below roughly 3–4 cubic yards most plants add $60–$150, because the truck and driver are committed regardless of how much they carry. It means a 2 yard pour can cost nearly as much in delivery as a 4 yard one, and it is worth asking about before you finalise dimensions.
Four inches of compacted aggregate under a slab is a genuine cost — often $400–$800 on a garage slab — and it is the item most often left out of a cheap quote. Seeing it as its own line makes an incomplete quote obvious.
Excavation and grading, forming, reinforcement, placing, finishing, control joints and cleanup. It does not include demolition of an existing slab, drainage work, or anything structural that needs an engineer.
Four inches over a 4 inch compacted base.
$3,456 – $5,760 installed
Material is roughly a quarter of the low end. If someone quotes $2,000 for this slab, they are quoting material and a day, not a finished slab.
Identical concrete, decorative finish.
$6,912 – $11,520 installed
Double the broom-finish price for the same volume of concrete. The entire difference is labour, colour and sealer.
Small pour, right in short-load territory.
$720 – $1,200 installed
The short-load fee is nearly 40% of the material cost here. Small slabs carry a disproportionate share of fixed costs.
2026 US averages, including labour, forming and reinforcement.
| Finish | Per ft² | 576 ft² garage slab |
|---|---|---|
| Broom | $6–$10 | $3,456–$5,760 |
| Smooth trowel | $7–$12 | $4,032–$6,912 |
| Polished | $10–$18 | $5,760–$10,368 |
| Stamped | $12–$20 | $6,912–$11,520 |
| Exposed aggregate | $10–$16 | $5,760–$9,216 |
Typical split on a broom-finished residential slab.
| Item | Share |
|---|---|
| Labour — forming, placing, finishing | 40–50% |
| Ready-mix concrete | 25–35% |
| Aggregate base | 8–12% |
| Reinforcement | 5–8% |
| Excavation and grading | 5–10% |
| Item | Typical cost |
|---|---|
| Demolition of existing slab | $2–$6 per ft² |
| Short-load fee, under 4 yd³ | $60–$150 |
| Colour, integral | $1–$3 per ft² |
| Sealer | $0.50–$1.50 per ft² |
| Thickened edge | $5–$10 per linear ft |
| Pump truck, restricted access | $800–$1,500 |
The useful question is not what a slab costs but what share of the quote is labour — because that is what varies between contractors, and it is where an unusually low number is usually coming from.
Usually the base, the reinforcement, or the excavation. A slab poured straight onto graded soil with no aggregate and no mesh is cheaper to build and will crack within a few winters. Ask for base depth in inches and reinforcement type in writing.
A truck that can back up to the forms and chute directly is the cheapest case. If concrete has to be pumped or barrowed, add $800–$1,500 for a pump or a great deal of labour for wheelbarrows. This is often the single biggest driver of quote variance on back-garden slabs.
Under about 1 cubic yard, bagged concrete and a mixer is realistic for a competent DIYer. Above that you are placing and finishing several tons against a setting clock, and finishing is a skill — a badly floated slab cannot be fixed afterwards.
Cold-weather pours need blankets, accelerators or heated enclosures, all of which add cost. Hot weather brings retarders and early-morning starts. Spring and autumn are the cheapest and the easiest to schedule.
The most common way to be misled. A slab on 4 inches of compacted aggregate and one poured on bare soil are different products at different prices, and the quote sheets can look identical.
It is a quarter to a third of the job. Shopping mix suppliers to save $10 per yard moves an $8,000 slab by under $100.
Concrete cracks — the only question is whether it cracks where you decided. Control joints cut within 24 hours at roughly 24–36 times the slab thickness in feet are what keep cracking straight and hidden.
Mesh or rebar does not stop cracks forming; it holds the two sides together so the slab stays flat and level afterwards. On anything carrying vehicles it is not optional.
A back-garden slab that needs a pump can cost $1,000 more than an identical one at the front of the house. Work out how the concrete physically reaches the forms before comparing prices.
$6–$10 per square foot installed for a broom finish in 2026, so a 24 × 24 ft garage slab runs about $3,456–$5,760. Stamped or polished finishes roughly double that for the same concrete.
Typically 25–35%. Labour is 40–50%, with base, reinforcement and excavation making up the rest. Shopping mix suppliers to save $10 per yard barely moves the total.
A surcharge of $60–$150 that most ready-mix plants add below 3–4 cubic yards, because the truck is committed regardless of load size. It means a 2 yard pour can cost nearly as much in delivery as a 4 yard one.
The concrete is identical — the difference is entirely labour, colour, release agent, stamping mats and sealer. Expect $12–$20 per square foot against $6–$10 for a broom finish.
It should, but often it is not stated. Four inches of compacted aggregate under a slab is a real cost — $400–$800 on a garage slab — and it is the item most often missing from a cheap quote.
$2–$6 per square foot including disposal, depending on thickness and whether it is reinforced. Reinforced slabs cost more because the steel has to be cut.
Under about a cubic yard, realistically yes. Above that you are placing and finishing several tons against a setting clock, and finishing is a skill — a badly floated slab cannot be corrected afterwards.
Access is usually the biggest factor. A truck that can chute directly into the forms is the cheapest case; if concrete must be pumped, add $800–$1,500. Finish type and base depth account for most of the rest.
Concrete Slab Cost per Square Foot — A standard broom-finish slab installs at $6–$12 per square foot in 2026. This guide shows where in that range your project lands, and what the per-square-foot number hides.
Asphalt vs Concrete Driveway — Asphalt installs at $4–$7 per square foot and concrete at $6–$12 — but the upfront price is the least interesting difference. Here is the comparison over the life of the driveway.
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This calculator uses published constants from named industry sources, each asserted in an automated test that runs on every build. The formula is printed with the result above, and any correction we make is logged on the changelog.
It is a planning estimate. It does not replace an engineer, a site visit or a written quote — confirm quantities with your supplier before ordering.