Concrete Slab Cost Estimator
Enter the slab dimensions for installed concrete pricing.
Runs entirely in your browser — your numbers never leave this page.
How it works
Installed slab = area × thickness rate (+ reinforcement):
- 4" (~$8.50/sq ft): patios, sheds, walkways — light loads.
- 6" (~$10.50/sq ft): driveways, garage floors — vehicle loads.
- 8" (~$13/sq ft): heavy equipment, structural — engineered.
- Rebar/mesh (+$1.25/sq ft): cheap insurance against cracking — always worth it.
- Base prep: 4" of compacted gravel under the slab is included in pro pricing; DIY often skips it and regrets it.
- Curing: keep it damp 7 days — the strongest concrete is the slowest-dried.
Frequently asked questions
How much does a concrete slab cost?
About $8.50/sq ft (4"), $10.50 (6"), $13 (8") installed, plus ~$1.25/sq ft for rebar/mesh.
How much is a 24×24 garage slab?
576 sq ft × $10.50 ≈ $6,000 plus rebar — roughly $6,700 installed.
How thick should my slab be?
4" for patios/sheds, 6" for driveways/garages, 8"+ for heavy loads. Thicker is not automatically better — match the load.
Do I need rebar?
Yes — ~$1.25/sq ft of cheap insurance. Mesh for light slabs, rebar for driveways and structural work.
How many yards of concrete?
Length × width × thickness(ft) ÷ 27, plus 10% waste. This calculator shows it.
Can I pour it myself?
Small pads yes; anything over a few yards wants a ready-mix truck and experienced finishers — concrete waits for no one.
How long before I can drive on it?
7 days for vehicles (28 for full strength). Patience now prevents cracks later.
Why do slabs crack?
No control joints, poor base, or fast drying. Joints every 8–12 ft give cracks somewhere to go.
Do I need a permit?
Usually yes for structural slabs and driveways; small shed pads often exempt. Check locally.
What about the gravel base?
4" of compacted gravel is standard and included in pro pricing — it's what keeps the slab from settling.