Concrete Slab Cost Calculator
Price the slab the way it actually gets billed: ready-mix by the yard plus delivery and short-load fees, compared against bagged mix, then base gravel, reinforcement and labor.
Quick answer
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Slab
Ready-mix pricing
Bagged mix pricing
40, 50, 60 or 80
Base, steel and labor
Mesh ≈ $0.35, #4 grid ≈ $0.85
Set to 0 for a DIY pour
ready-mix = yards x $/yd³ + delivery + max(0, minimum − yards) x short-load fee
Cost summary
Concrete delivered
$1,028
5.5 yd³ + $120 delivery
Bagged alternative
$1,838
245 x 80 lb bags
Materials total
$1,744
Concrete + base gravel + reinforcement
Installed total
$3,344
$8 per sq ft
Line items
| Item | Quantity | Cost |
|---|---|---|
| Concrete | 5.5 yd³ | $908 |
| Delivery | 1 truck | $120 |
| Short-load fee | 0 yd³ short | $0 |
| Base gravel | 9.9 tons | $376 |
| Reinforcement | 400 sq ft | $340 |
| Labor | 400 sq ft | $1,600 |
Slab volume 4.94 yd³ before waste, 5.43 yd³ with 10% waste, 11 tons placed.
What actually drives slab cost
Concrete itself is rarely the biggest line. On a typical residential slab the mix is 25 to 35 percent of the installed price; forming, base preparation, reinforcement and finishing labor make up the rest. That is why a 20 x 20 ft slab does not cost twice a 10 x 20 ft slab — the fixed costs of a truck, forms and a crew spread across more area.
Watch the truck minimum. A 1.5 yard order on a 4 yard minimum can carry more in short-load fees than the concrete costs, which is the one case where mixing bags on site genuinely wins.
Thickness is linear in cost, so specify what the use needs: 4 inches for foot traffic, 5 to 6 where a vehicle parks. Skipping base gravel to save money is the false economy — the slab cracks where the subgrade settles, and that repair costs more than the stone would have.
Source & method: Cost model computed in your browser from the volume geometry plus the unit prices you enter. Default prices are typical US ranges as of 2026 and are editable — nothing is fetched from a paid database.
Base prep gear
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- Plate compactorCompact base gravel in lifts or the slab will crack where it settles.Base prep · Check price
- Hand tamperFor trench bottoms and tight corners a plate cannot reach.Check price
- Landscape fabricSeparates base stone from subgrade so it stops pumping mud.Check price
- Laser level or line levelSet grade before the material lands, not after.Check price
Forming supplies
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- Form stakes (24 in steel)4 in slabHold form boards to line and grade against the pressure of wet mix.Check price
- Expansion joint stripIsolate the slab from footings, walls and adjoining concrete.Check price
- Vapor barrier (6 mil poly)Required under interior slabs and worth it under any garage floor.Check price
- Concrete cure and sealHolds moisture in for the first week so the slab reaches strength.Check price
Frequently asked questions
- How much does a concrete slab cost?
- Material alone runs about $140 to $190 per cubic yard of ready-mix delivered, which is roughly $2 to $3 per square foot at 4 inches thick. A finished slab installed by a contractor typically costs $6 to $12 per square foot because labor, forming, base gravel and reinforcement are the larger share.
- Is it cheaper to pour concrete yourself or buy bags?
- Bags are cheaper below about half a cubic yard and much more expensive above one yard: 80 lb bags work out near $340 per cubic yard of finished concrete at $7.50 a bag, against $165 for ready-mix. Bags win only when the pour is too small to justify a truck.
- What is a short-load fee?
- Ready-mix plants charge a per-yard penalty when your order is under the truck minimum, commonly 3 to 5 yards. The fee is often $30 to $60 for every yard short, so a 2-yard order on a 4-yard minimum can add $60 to $120.
- Does a thicker slab cost much more?
- Cost scales directly with thickness: going from 4 to 6 inches is 50 percent more concrete. On a 400 sq ft slab that is about 2.5 extra cubic yards, so roughly $400 more in material.
Related calculators & charts
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- Cubic Yard CalculatorConvert any length, width and depth into cubic yards, feet and tons.
- Gravel CalculatorTons and cubic yards of gravel, crushed stone or road base for any area.
- Sand CalculatorBedding, paver and fill sand quantities by volume, weight and bag count.