Concrete Slab Cost Calculator

Use this concrete slab cost calculator to estimate material volume and total project cost based on slab dimensions and thickness. Designed for driveways, patios, garage floors, and foundations using standard US measurements to help homeowners and contractors plan accurate budgets before pouring concrete.

By ConstructlyTools · Published: January 12, 2025 · Updated: March 14, 2026
Concrete Slab Cost Calculator
📐 Formula Used
Total Cost = Slab Area (sq ft)
× (Material + Labor + Finish) Cost per sq ft
Total Estimated Cost
$0 – $0
Enter measurements above to get your estimate
Slab Area
0 sq ft
Concrete (cu yd)
0 cu yd
Material Cost
$0 – $0
Labor Cost
$0 – $0

Standard finish $4–$8/sq ft · Exposed aggregate $6–$10/sq ft · Stamped $8–$18/sq ft · Colored $5–$10/sq ft (installed) · Includes concrete + labor

Estimates based on 2026 US average pricing. Actual costs vary by region. Always get 3 quotes before starting.

How Does the Concrete Slab Cost Calculator Work?

This concrete slab cost calculator estimates the total cost of pouring a concrete slab based on dimensions, thickness, finish type, and labor. It also calculates how many cubic yards of concrete you'll need. Uses 2026 US average pricing.

Steps:

  1. Enter your slab length and width in feet.
  2. Select your slab thickness — 4 inches for patios and walkways, 6 inches for driveways and garage floors.
  3. Select your concrete finish — standard broom, exposed aggregate, stamped, or colored.
  4. Choose DIY or Contractor for labor.
  5. Get instant results — total cost, cost per sq ft, slab area, cubic yards needed, material cost, and labor cost.
💡 Pro Tip

Always add 10% extra when ordering concrete for waste and overrun. A short load fee from ready-mix companies applies if you order less than a minimum (usually 1 cubic yard) — always confirm minimums with your supplier.

Concrete Slab Cost by Type (2026)

Here's a full breakdown of 2026 US average installed costs per square foot for all 4 concrete finishes, plus a typical 400 sq ft slab total at each thickness.

Finish TypeInstalled $/sq ft (4")Installed $/sq ft (6")400 sq ft Total (6")Best For
Standard Broom$4 – $8$5 – $10$2,000 – $4,000Driveways, garage floors
Colored Concrete$5 – $10$6 – $12$2,400 – $4,800Patios, decorative slabs
Exposed Aggregate$6 – $10$7 – $12$2,800 – $4,800Pool decks, patios
Stamped Concrete$8 – $18$10 – $20$4,000 – $8,000Decorative patios, entries

*Installed cost includes concrete material, labor, forming, finishing, and curing. Rebar is additional — use our Rebar Calculator to estimate.

💰 Best Value Pick

Standard broom finish is the most affordable and most durable for functional slabs like driveways and garage floors. Stamped concrete is beautiful but costs 2–3× more and requires resealing every 2–3 years to maintain appearance.

Example Calculation

You want to pour a standard broom finish concrete slab, 20 ft × 20 ft, 6 inches thick, hired contractor.

Step 1 — Calculate slab area:

20 ft × 20 ft = 400 sq ft

Step 2 — Calculate cubic yards:

400 × (6÷12) ÷ 27 = 400 × 0.5 ÷ 27 = 7.4 cubic yards (order 8.2 with 10% waste)

Step 3 — Material cost ($2–$4/sq ft):

400 × $2 = $800  |  400 × $4 = $1,600
Material: $800 – $1,600

Step 4 — Labor cost ($3–$6/sq ft):

400 × $3 = $1,200  |  400 × $6 = $2,400
Labor: $1,200 – $2,400

Step 5 — Total estimated cost:

$2,000 – $4,000 ($5 – $10 per sq ft)

Factors That Affect Concrete Slab Cost

Site Preparation

Excavation, grading, and base preparation add $1–$3 per sq ft. Rocky soil or sloped sites can significantly increase prep costs. A properly prepared 4–6 inch compacted gravel base is essential for slab longevity.

Rebar & Wire Mesh

Rebar reinforcement adds $0.35–$0.60 per sq ft for materials. Wire mesh adds $0.10–$0.30 per sq ft. Both improve crack resistance — rebar is recommended for driveways and structural slabs.

Concrete Mix & PSI

Standard residential concrete is 3,000–4,000 PSI. Higher PSI mixes for heavy loads or freeze-thaw climates cost 10–20% more. Fiber-reinforced concrete adds $2–$5 per cubic yard.

Removal of Existing Concrete

Breaking up and hauling away existing concrete adds $2–$6 per sq ft. A 400 sq ft slab costs $800–$2,400 extra to remove before new concrete is poured.

Permits

Most municipalities require permits for concrete slabs over 200 sq ft or attached to a structure. Permits typically cost $100–$300. Always check local codes — especially for driveways connecting to a public road.

⚠️ Always Get 3 Quotes

Concrete contractor pricing varies widely. Get 3 itemized quotes. Ask each to break out site prep, formwork, concrete material, finishing, rebar, and any removal fees separately.

Frequently Asked Questions

How much does a concrete slab cost per square foot?+
A standard concrete slab costs $5–$10 per square foot installed for a basic broom finish at 6 inches thick. Stamped concrete runs $10–$20/sq ft. Colored concrete is $6–$12/sq ft. These prices include concrete material and labor but not rebar, site prep, or permits.
How much does a 20×20 concrete slab cost?+
A 20×20 ft concrete slab (400 sq ft) at 6 inches thick costs approximately $2,000–$4,000 for a standard broom finish installed. Stamped concrete for the same slab would run $4,000–$8,000. Add $800–$2,400 if existing concrete needs to be removed first.
How thick should a concrete slab be?+
4 inches is standard for patios, sidewalks, and light-duty slabs. 6 inches is recommended for driveways and garage floors that support vehicle traffic. 8 inches is used for commercial slabs, heavy equipment areas, and foundations.
How many cubic yards of concrete do I need?+
Calculate cubic yards using: Length × Width × (Thickness in inches ÷ 12) ÷ 27. For a 20×20 ft slab at 6 inches: 20 × 20 × (6÷12) ÷ 27 = 7.4 cubic yards. Always order 10% extra to account for waste and overrun. Use our Concrete Calculator for a more detailed estimate.
Is stamped concrete worth the extra cost?+
Stamped concrete looks great and costs significantly less than natural stone pavers, but it requires resealing every 2–3 years to maintain color and protection. If you're willing to do the maintenance, stamped concrete is excellent value. If you want zero maintenance, concrete pavers are a better long-term choice.
How accurate is this concrete slab cost calculator?+
Very accurate for planning and budgeting. It uses 2026 US national average pricing for 4 finish types at multiple thicknesses. Rebar, site prep, and permits are not included in the estimate. Always get 3 contractor quotes to confirm your final number.
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