30x30 Concrete Slab Cost and How to Pour It
A 30x30 concrete slab costs $7,324 to $12,206 installed with rebar at 4 inches. Enter your ZIP or change the thickness in the calculator to see your own figure.
LIKELY INSTALLED PRICE
$9,765
Our installed range for this 30×30 ft, 4-inch slab: $7,324 – $12,206 ($8.14 – $13.56 per sq ft)
In plain terms: that's about the size of a three-car garage floor, and roughly 45% of the price is the crew's labor.
- DIY materials
- $5,181
- Concrete
- 11.11 yd³
- Bagged mix
- 550 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$4,456
- Labor$3,682
- Overhead and profit (20%)$1,627
All 8 line items
| Item | Qty | Material | Labor | Total |
|---|---|---|---|---|
| Site setup, layout and cleanup | 1 job | $100 | $56 | $156 |
| Excavate and grade subgrade | 900 sqft | $0 | $999 | $999 |
| Forms, stakes and form release | 120 lf | $144 | $266 | $410 |
| Compacted crushed-stone base | 15.56 ton | $700 | $288 | $988 |
| #4 rebar, tied on chairs | 1,260 lf | $1,257 | $559 | $1,816 |
| Ready-mix concrete, 3,500 psi, delivered | 11.67 yd3 | $2,030 | $259 | $2,289 |
| Place, screed and broom finish | 900 sqft | $45 | $1,166 | $1,211 |
| Sawn control joints | 120 lf | $180 | $89 | $269 |
| Subtotal × overhead and profit (20%) = midpoint | $9,765 | |||
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 $7,324 – $12,206. DIY: 550 bags or 11.67 yd³ of ready-mix.
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Turn this price into an estimate for your customer →Cost by thickness for 30x30 (900 sq ft)
4 in · patios, sheds
$7,324 – $12,206
11.11 yd³ · 550 bags · about $9,765
5 in · garages, driveways
$7,838 – $13,064
13.89 yd³ · 688 bags · about $10,451
6 in · shops, RV pads
$8,232 – $13,721
16.67 yd³ · 826 bags · about $10,977
- Typical use
- A three-car garage or a small shop floor.
- Thickness
- 4 inches with rebar for cars; 5 to 6 inches for a shop with heavy tools or a lift.
- Planning note
- A slab this size should be divided into panels by saw cuts, or cracks will choose their own lines.
Cost for a 30x30 concrete slab
At 900 square feet the price is mostly concrete and finishing labor. Gravel, 1,260 linear ft of rebar and forming along 120 linear ft are listed separately above.
How to pour a 30x30 concrete slab
Excavate, compact 15.6 tons of base, set forms and lay the rebar on chairs. Pour in sections from the far side, screed, float and trowel, then saw control joints within a day.
Concrete order and crew size
Order 11.67 yd³ on 2 trucks. A slab this size needs a pump or a close truck and at least three finishers.
What this number is and isn't
It's a national-data estimate for planning, not a price anyone has offered you. Use it to judge bids, then sign the written one that matches your site.
DIY vs pro for this 30x30 pour
Materials alone come to $5,181, about 53% of the $9,765 midpoint contractor price. The difference is $4,584 of labor, equipment, delivery and contractor overhead across 8 line items. At 11.67 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
- 24x24 concrete slab cost$4,848 – $8,080576 sq ft · 7.11 yd³ at 4 in
- 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
- 30x40 concrete slab cost$9,664 – $16,1061,200 sq ft · 14.81 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
Compare with the next sizes
Garage concrete slab cost calculatorAll slab sizes and the full calculator
Frequently asked questions
How many yards of concrete for a 30x30 slab?
11.11 yd³ at 4 inches, or 11.67 yd³ with the usual extra. A thicker slab raises that quickly.
Can one person finish a 30x30 slab?
No. The concrete sets faster than one person can work it, so plan several finishers and a power trowel.
Is a 30x30 slab cheaper per foot than a smaller one?
Usually, yes. At $8.14 – $13.56 it spreads setup and delivery over 900 square feet.
Does a 30x30 garage slab need an engineer?
Not always, but a building permit for a structure this size often asks for stamped plans. Your building department can tell you.
For contractors
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