30x40 Concrete Slab Cost for a Shop
A 30x40 concrete slab costs $9,664 to $16,106 installed at 4 inches with rebar. Add your ZIP to the calculator for local labor, or change the thickness for heavier equipment.
LIKELY INSTALLED PRICE
$12,885
Our installed range for this 30×40 ft, 4-inch slab: $9,664 – $16,106 ($8.05 – $13.42 per sq ft)
In plain terms: that's about the size of a workshop or pole-barn floor, and roughly 45% of the price is the crew's labor.
- DIY materials
- $6,878
- Concrete
- 14.81 yd³
- Bagged mix
- 734 80-lb bags
- Delivery
- 2 trucks
An estimate, not a bid. A contractor's price depends on your site, access and timing.
What changes the price
Where the money goes
- Materials$5,888
- Labor$4,849
- Overhead and profit (20%)$2,147
All 8 line items
| Item | Qty | Material | Labor | Total |
|---|---|---|---|---|
| Site setup, layout and cleanup | 1 job | $100 | $56 | $156 |
| Excavate and grade subgrade | 1,200 sqft | $0 | $1,332 | $1,332 |
| Forms, stakes and form release | 140 lf | $168 | $311 | $479 |
| Compacted crushed-stone base | 20.74 ton | $933 | $384 | $1,317 |
| #4 rebar, tied on chairs | 1,670 lf | $1,666 | $742 | $2,407 |
| Ready-mix concrete, 3,500 psi, delivered | 15.56 yd3 | $2,706 | $345 | $3,052 |
| Place, screed and broom finish | 1,200 sqft | $60 | $1,554 | $1,614 |
| Sawn control joints | 170 lf | $255 | $126 | $381 |
| Subtotal × overhead and profit (20%) = midpoint | $12,885 | |||
National prices until you enter a ZIP.
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Compare a contractor's price with the range for these inputs.
What next
Get two or three quotes and compare them with $9,664 – $16,106. DIY: 734 bags or 15.56 yd³ of ready-mix.
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Turn this price into an estimate for your customer →Cost by thickness for 30x40 (1,200 sq ft)
4 in · patios, sheds
$9,664 – $16,106
14.81 yd³ · 734 bags · about $12,885
5 in · garages, driveways
$10,350 – $17,251
18.52 yd³ · 917 bags · about $13,800
6 in · shops, RV pads
$10,896 – $18,160
22.22 yd³ · 1,100 bags · about $14,528
- Typical use
- A metal-building shop or a pole barn floor.
- Thickness
- 4 inches with rebar for cars; 6 inches under lifts and heavy equipment.
- Planning note
- Put floor drains, trench drains and any under-slab plumbing in before the pour.
30x40 concrete slab cost for a shop
At 1,200 square feet, concrete and finishing labor make up most of the bill. The line items break out 1,670 linear ft of rebar, 20.7 tons of gravel and forming along 140 linear ft.
Shop floor thickness and equipment
The 4-inch price suits cars and hand tools. For a vehicle lift or a heavy machine, raise the thickness in the calculator to see the new concrete volume and cost.
Ordering concrete for a 30x40
It takes 15.56 yd³ with waste, which is 2 trucks. Schedule the trucks close together so each section can be finished before the last one sets.
Anchor bolts for a metal building
Steel building kits come with an anchor bolt plan. The bolts go into the wet concrete to that plan, so bring the drawings on pour day. A bolt in the wrong spot means drilling and epoxy later.
Using the estimate
This is a planning estimate, not a bid. Bring the line items to contractors so their quotes cover the same work.
DIY vs pro for this 30x40 pour
Materials alone come to $6,878, about 53% of the $12,885 midpoint contractor price. The difference is $6,007 of labor, equipment, delivery and contractor overhead across 8 line items. At 15.56 yd³ with waste the pour fills 2 mixer trucks, so ready-mix is the practical route even for a DIY pour.
Other popular slab sizes
- 20x30 concrete slab cost$4,983 – $8,306600 sq ft · 7.41 yd³ at 4 in
- 20x40 concrete slab cost$6,562 – $10,936800 sq ft · 9.88 yd³ at 4 in
- 30x30 concrete slab cost$7,324 – $12,206900 sq ft · 11.11 yd³ at 4 in
- 30x50 concrete slab cost$12,004 – $20,0061,500 sq ft · 18.52 yd³ at 4 in
- 40x40 concrete slab cost$12,766 – $21,2761,600 sq ft · 19.75 yd³ at 4 in
- 40x60 concrete slab cost$18,970 – $31,6172,400 sq ft · 29.63 yd³ at 4 in
Compare with the next sizes
Garage concrete slab cost calculatorAll slab sizes and the full calculator
Frequently asked questions
How many yards of concrete is a 30x40 slab?
14.81 yd³ at 4 inches, or 15.56 yd³ ordered. At 6 inches it's half again as much.
What does a 30x40 metal building slab include?
This estimate is a flat slab with rebar. Perimeter footings for a metal building are priced on the foundation page.
Is a 30x40 slab worth doing yourself?
Most owners hire the pour. At 14.81 yd³ you need a crew, a pump or close truck access, and power trowels.
How long does a 30x40 slab need to cure?
Foot traffic is usually fine within a day or two. Heavy vehicles should wait for the full cure time your supplier gives.
For contractors
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