40×80 Concrete Slab Cost
A 40×80 slab covers 3,200 square feet. Here's the concrete, bags and cost for 2026 — a common size for a commercial pad.
Concrete (4", waste in)
43.46 yd³
1,956 × 80 lb bags
Materials (ready-mix)
$5,432 – $8,257
delivered, 4" slab
Installed by a pro
$17,600 – $38,400
4" slab, national average
40×80 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
$17,600 – $38,400
3,200 sq ft · 43.46 yd³ concrete
Bags of concrete needed (rounded up)
1,956
80 lb
2,608
60 lb
3,129
50 lb
3,912
40 lb
- Ready-mix (delivered)
- $5,432 – $8,257
- Bagged mix (80 lb, DIY)
- $10,758 – $17,604
- Installed by a pro
- $17,600 – $38,400
Estimate only — not a quote. Bag counts are rounded up and include a 10% waste allowance.
40×80 slab cost by thickness
| Thickness | Concrete | 80 lb bags | Ready-mix | Installed |
|---|---|---|---|---|
| 4" | 43.46 yd³ | 1,956 | $5,432 – $8,257 | $17,600 – $38,400 |
| 5" | 54.32 yd³ | 2,445 | $6,790 – $10,321 | $20,000 – $40,800 |
| 6" | 65.19 yd³ | 2,934 | $8,148 – $12,385 | $22,400 – $43,200 |
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.
40×80 concrete slab: what to expect
A 40×80 slab covers 3,200 square feet. At the standard 4" thickness it takes about 43.46 cubic yards of concrete once you allow 10% for waste, which is roughly 1,956 × 80 lb bags if you mix by hand. Stepping up to 6" — sensible if it'll carry a vehicle — raises that to about 65.19 cubic yards.
Budget around $17,600 – $38,400 to have a 4" slab this size poured and finished by a contractor, or roughly $5,432 – $8,257 in ready-mix if you're doing the labor yourself. On top of the concrete you'll need about 45.43 yd³ of gravel base and 216 sticks of rebar.
Compare nearby sizes
Planning something bigger or smaller? Jump straight to the cost for a nearby size.
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: