Concrete Slab Cost Calculator
Get an instant free estimate for your concrete slab project.
How is Concrete Slab Cost Calculated?
The cost is primarily determined by Square Footage and Thickness (Volume). A 6-inch slab uses 50% more material than a 4-inch slab. Site preparation (grading, gravel) and specialized finishes (stamping) also add significantly to the price per square foot.
Calculate the Cost Estimate of Concrete Slab
Get started by entering your zip code for a localized estimate.
Slab Dimensions
Enter the length and width of the area.
Slab Thickness:
Reinforcement:
Additional Services:
Key Factors Influencing Concrete Rates
Thickness & Mix
4-inch Slab: Standard for patios, sidewalks, and garage floors.
6-inch Slab: Required for heavy loads, such as driveways for large trucks or RV pads. Uses more cement and labor.
Finish Quality
Broom Finish: Standard non-slip texture. Lowest cost.
Stamped/Decorative: High-end aesthetic that mimics stone or tile. Expensive due to color hardeners, release agents, and detailed labor.
Average Cost by Size (4" Slab)
| Dimensions | Area (Sq Ft) | Estimated Cost Amount |
|---|---|---|
| 10' x 10' (Shed Base) | 100 sq ft | $800 – $1,200 |
| 12' x 24' (Patio/Patio) | 288 sq ft | $1,800 – $2,800 |
| 20' x 20' (2-Car Garage) | 400 sq ft | $2,400 – $3,500 |
| 24' x 24' (Large Garage) | 576 sq ft | $3,500 – $5,000 |
Additional Service Fees
| Service | Estimated Cost | Note |
|---|---|---|
| Concrete Pump | $500 – $800 | Daily rental flat rate |
| Slab Removal | $4 – $8 / sq ft | Breaking and hauling old concrete |
| Vapor Barrier | $0.50 / sq ft | 6-mil poly sheet |
| Grading | $1 – $2 / sq ft | Leveling the sub-base |
How to Estimate Concrete Slab Cost Manually
Calculating concrete costs involves determining the volume of wet cement needed and adding labor for prep and finishing.
Step 1: Calculate Area
Multiply Length × Width. Example: 24 ft × 24 ft = 576 sq ft.
Step 2: Determine Base Rate
4-inch Slab: ~$6 – $8 per sq ft installed.
6-inch Slab: ~$8 – $10 per sq ft installed (requires 50% more concrete).
Step 3: Add Reinforcement & Prep
Wire mesh adds ~$0.50/sq ft. Rebar adds ~$1.00/sq ft. Grading and gravel base can add $1-$2/sq ft.
Step 4: Apply Formula
(Sq_Ft × Base_Rate) + (Sq_Ft × Reinforcement) + Add-ons = Total
Example: 400 sq ft patio (4") with Rebar. (400 × $7) + (400 × $1) = $3,200.
Frequently Asked Questions
Concrete takes 24-48 hours to dry enough to walk on, but 7 days to cure to ~70% strength, and 28 days to fully cure. You should not drive on a new driveway for at least 7-10 days.
For patios, walkways, and shed bases, 4 inches is standard. For driveways that will hold heavy vehicles (RVs, trucks) or heavy machinery, 6 inches is recommended for durability.
Rebar significantly strengthens concrete and prevents cracking. While wire mesh is cheaper and common for simple patios, rebar is highly recommended for driveways or any load-bearing slab.
Stamped concrete is textured and colored to resemble stone, brick, slate, or wood. It is a premium finish that requires more labor and materials, typically costing $12-$18+ per sq ft.
Yes, if the slab is for an indoor space (like a garage or basement) or if you plan to put flooring over it. It prevents ground moisture from seeping up through the porous concrete.
Yes. Concrete cannot be poured in freezing temperatures (without expensive additives) or heavy rain. High heat can also cause it to cure too fast and crack, so early morning pours are common in summer.
PSI (Pounds per Square Inch) measures compressive strength. 3000 PSI is standard for residential slabs. 4000 PSI is used for heavy-duty driveways or commercial workshop floors.
It is possible but risky. The new layer must be bonded correctly, or it will crack and flake off. Usually, it is better to remove the old slab and pour a fresh, full-depth slab.
Most cities require a permit for concrete work that alters impervious surface coverage (runoff) or touches the public right-of-way (like a driveway apron).
Usually, no. If the cement truck cannot reach the pour site (e.g., a backyard patio), a concrete pump is needed. This costs an extra $500-$800 per day.