Slab cost estimate
30x50 Concrete Slab Cost
A 30 ft × 50 ft concrete slab is 1500 square feet. At a standard 4-inch thickness it needs about 20.37 cubic yards of concrete (with 10 % waste) and costs roughly $9,000 – $19,500 installed with a plain broom finish.
Need different dimensions? Use the full Slab Cost Calculator for a custom estimate.
Material & Cost Breakdown
| Metric | Value | Notes |
|---|---|---|
| Square footage | 1500 sq ft | 30 ft × 50 ft |
| Thickness | 4 in | Standard residential |
| Concrete volume | 18.52 yd³ | Before waste |
| Order volume (10% waste) | 20.37 yd³ | Ready-mix ordering target |
| 80 lb bags needed | 917 bags | Including waste |
| 60 lb bags needed | 1223 bags | Including waste |
| Ready-mix material cost | $2,648 – $3,361 | ~$130–$165 per yard delivered |
| Installed cost (broom) | $9,000 – $19,500 | $6–$13 per sq ft |
* Installed cost assumes a standard broom finish, easy site access, and a prepared sub-base. Decorative finishes, tear-out, poor soil, or pump-truck access will move the price higher.
30x50 Slab Cost by Thickness
Thickness is the single biggest lever on how much concrete a 30x50 slab needs. A 4-inch pour suits patios and light foot traffic; step up to 5–6 inches for driveways, garages, shops, and anything carrying vehicles or heavy equipment. Each extra inch adds concrete volume and a little labor.
| Thickness | Concrete (10% waste) | Installed cost | Typical use |
|---|---|---|---|
| 4 in (standard) | 20.37 yd³ | $9,000 – $19,500 | Patios, walkways, light foot traffic |
| 5 in | 25.46 yd³ | $9,900 – $20,400 | Driveways, standard garages |
| 6 in | 30.56 yd³ | $10,800 – $21,300 | Shops, RV pads, heavy equipment |
How We Calculated It
- Area: 30 ft × 50 ft = 1500 sq ft
- Volume: 1500 sq ft × (4 in ÷ 12) = 500.0 cu ft ÷ 27 = 18.52 yd³
- With 10% waste: 18.52 × 1.10 = 20.37 yd³
- Bags (80 lb): 20.37 × 27 ÷ 0.60 cu ft/bag ≈ 917 bags
FAQs
How much does a 30x50 concrete slab cost?
A 30x50 (1500 sq ft) concrete slab costs roughly $9,000 to $19,500 installed with a broom finish in 2026. Decorative finishes, tear-out, and site prep can raise the price.
How many cubic yards for a 30x50 slab?
At 4 inches thick, a 30x50 slab needs about 18.52 cubic yards before waste and 20.37 yards after a 10% ordering allowance.
How many 80 lb bags for a 30x50 slab?
You would need about 917 bags of 80 lb concrete (including 10% waste). Above roughly one cubic yard, ready-mix is usually cheaper and easier than bags.
How much does a 30x50 slab cost at 6 inches thick?
A 6-inch 30x50 slab needs about 30.56 cubic yards of concrete and typically runs $10,800 to $21,300 installed. The thicker pour adds concrete volume, so it costs more than the standard 4-inch slab but resists cracking under vehicles and heavy loads.
Planning Your 30x50 Pour
When preparing to pour a 30 ft × 50 ft concrete slab, proper planning is essential to keep your project on budget. The dimensions directly determine the total square footage, which in turn dictates the amount of labor, forming materials, and finishing time required.
The thickness is equally important. While 4 inches is standard for this type of slab, increasing the thickness by just one inch will significantly increase the total cubic yards of concrete needed. Always ensure your sub-base is properly compacted and leveled; an uneven base can lead to thick spots that consume more concrete than your initial estimate predicted. Lastly, ordering with a 10% waste margin is a standard industry practice to account for minor spills, uneven ground, and the small amount of concrete left inside the delivery truck.