Prices updated January 2026

1,500 sq ft Concrete Slab Cost

A 1,500 sq ft slab (about 30×50 ft) covers 1,500 square feet. Here's the concrete, bags and cost for 2026 — a common size for a shop / small warehouse.

Concrete (4", waste in)

20.37 yd³

917 × 80 lb bags

Materials (ready-mix)

$2,546 – $3,870

delivered, 4" slab

Installed by a pro

$8,250 – $18,000

4" slab, national average

1,500 sq ft slab cost calculator

Adjust thickness, waste or region — the cost updates live.

Width (ft)

Length (ft)

Thickness (in)

Waste & region

Waste factor (%)

Order extra for spillage & uneven subgrade. 10% is typical.

Region (cost)

Installed cost estimate

$8,250 – $18,000

1,500 sq ft · 20.37 yd³ concrete

Bags of concrete needed (rounded up)

917

80 lb

1,223

60 lb

1,467

50 lb

1,834

40 lb

Ready-mix (delivered): $2,546 – $3,870
Bagged mix (80 lb, DIY): $5,044 – $8,253
Installed by a pro: $8,250 – $18,000

Estimate only — not a quote. Bag counts are rounded up and include a 10% waste allowance.

Installed $8,250 – $18,000

1,500 sq ft slab cost by thickness

Thickness	Concrete	80 lb bags	Ready-mix	Installed
4"	20.37 yd³	917	$2,546 – $3,870	$8,250 – $18,000
5"	25.46 yd³	1,146	$3,183 – $4,838	$9,375 – $19,125
6"	30.56 yd³	1,375	$3,820 – $5,806	$10,500 – $20,250

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.

Gravel base

21.3 yd³

4" compacted base under the slab

≈ $639 – $1,384

Open calculator

Rebar

104 sticks

#4 bar, 18" grid (55 bars)

≈ $728 – $1,352

Open calculator

Bedding sand

4.63 yd³

~1" leveling layer

≈ $130 – $269

Open calculator

1,500 sq ft concrete slab: what to expect

A 1,500 sq ft slab (about 30×50 ft) covers 1,500 square feet. At the standard 4" thickness it takes about 20.37 cubic yards of concrete once you allow 10% for waste, which is roughly 917 × 80 lb bags if you mix by hand. Stepping up to 6" — sensible if it'll carry a vehicle — raises that to about 30.56 cubic yards.

Budget around $8,250 – $18,000 to have a 4" slab this size poured and finished by a contractor, or roughly $2,546 – $3,870 in ready-mix if you're doing the labor yourself. On top of the concrete you'll need about 21.3 yd³ of gravel base and 104 sticks of rebar.

Compare nearby sizes

Planning something bigger or smaller? Jump straight to the cost for a nearby size.

Size	Concrete (4")	80 lb bags	Installed cost
1,000 sq ft	13.58 yd³	612	$5,500 – $12,000
30×40	16.3 yd³	734	$6,600 – $14,400
30×50	20.37 yd³	917	$8,250 – $18,000
40×40	21.73 yd³	978	$8,800 – $19,200
30×60	24.44 yd³	1,100	$9,900 – $21,600
40×50	27.16 yd³	1,223	$11,000 – $24,000

See all common slab sizes →

Prices updated January 2026 National US averages · reviewed quarterly

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:

Slab cost by project

Concrete Slab Cost Cost per sq ft + calculator Garage Slab Cost Typical 20×20 / 24×24 Driveway Slab Cost Concrete vs asphalt Patio Slab Cost 10×10 to 20×20 Shed Base Cost Small pads

Frequently asked questions

How much does a 1,500 sq ft concrete slab cost?

A 1,500 sq ft slab (1,500 sq ft) costs about $8,250 – $18,000 installed at 4" thick in 2026, or $10,500 – $20,250 at 6". DIY in materials, the ready-mix runs about $2,546 – $3,870 at 4".

How many yards of concrete for a 1,500 sq ft slab?

At 4" thick a 1,500 sq ft slab needs about 20.37 cubic yards including 10% waste (18.52 yd³ net). At 6" it needs about 30.56 cubic yards.

How many bags of concrete for a 1,500 sq ft slab?

At 4" you'd need roughly 917 × 80 lb bags, 1,223 × 60 lb bags or 1,834 × 40 lb bags. That's a lot of mixing — past about a cubic yard, ready-mix is usually cheaper and easier.

What base and rebar does a 1,500 sq ft slab need?

Plan on about 21.3 cubic yards of compacted gravel base and roughly 104 sticks of #4 rebar on an 18" grid. The "You'll also need" cards size these for you.