How Much Does a Concrete Slab Cost? (2026)

A concrete slab costs $5 to $10 per square foot for basic installations, or $3,000 to $6,000 for a typical 400 sq ft patio or garage pad. Here is how thickness, finishing, and project scope affect your total.

By: CalcHub Editorial Operated by: Cloudtopia
Maintenance: Updated when formulas, supplier packaging, or guidance change.
Method: Research + supplier/manufacturer guidance + calculator cross-checks.
Cost Level Per Sq Ft (Installed) 400 Sq Ft Slab What You Get
Low$5–$8$2,000–$3,2004-inch slab, broom finish, wire mesh
Mid$8–$12$3,200–$4,8004-inch slab, rebar, smooth or exposed aggregate finish
High$12–$20+$4,800–$8,000+Stamped or colored concrete, 5-6 inch thickness, decorative borders

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How much does a concrete slab cost?

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Material Cost Breakdown

Concrete is priced per cubic yard — one yard covers 81 sq ft at 4 inches thick. Understanding the per-yard costs helps you budget accurately.

Ready-mix concrete: $140 to $170 per cubic yard delivered from a batch plant (2026 pricing). This is the standard for any slab larger than about 50 sq ft. A 400 sq ft slab at 4 inches needs about 5 cubic yards — roughly $700 to $850 for concrete alone. Short-load fees of $30 to $50 per yard apply if you order less than the minimum (usually 3 to 5 yards). Use our concrete calculator to determine your exact volume.

Bag-mix concrete: $5 to $7 per 80 lb bag. Each bag yields about 0.6 cubic feet. You would need roughly 225 bags to pour a 400 sq ft slab at 4 inches — costing $1,125 to $1,575 and requiring enormous labor. Bag mix is practical only for small pads under 50 sq ft.

Gravel sub-base: $30 to $50 per cubic yard. A 4-inch gravel base under a 400 sq ft slab needs about 5 cubic yards — roughly $150 to $250. This provides drainage and prevents the slab from cracking due to soil movement.

Reinforcement: Rebar (#3 or #4, laid on 18-inch centers) costs $0.75 to $1.50 per sq ft ($300 to $600 for 400 sq ft). Wire mesh is cheaper at $0.40 to $0.60 per sq ft ($160 to $240) but provides less crack resistance. For garage floors and driveways, rebar is worth the upgrade.

Formwork: 2x4 or 2x6 lumber for forms runs $100 to $250 for a 400 sq ft slab. Forms can often be reused or salvaged after the pour.

Labor Costs: DIY vs Contractor

DIY cost: For small slabs (under 100 sq ft), bag-mix and hand tools keep costs to $4 to $7 per sq ft. For larger slabs with ready-mix delivery, you still save on labor but need at least 2 to 3 helpers to pour and finish before the concrete sets. Budget $2,000 to $3,500 for materials on a 400 sq ft slab.

Contractor cost: Labor adds $3 to $8 per sq ft depending on complexity. A basic broom-finish patio slab is at the low end; a stamped or colored decorative slab is at the high end. Most contractors charge a minimum of $1,500 to $2,500 for any concrete job regardless of size — so small pads cost proportionally more per square foot. A typical 400 sq ft patio slab runs $3,000 to $5,000 all-in.

Cost by Slab Type

Patio slab: 4 inches thick, broom or smooth finish. $5 to $10 per sq ft installed. The most common and economical option.

Garage floor: 5 to 6 inches thick with rebar and thickened edges. $7 to $12 per sq ft installed. The extra thickness and reinforcement support vehicle weight.

Driveway: 5 to 6 inches with rebar, often with control joints every 8 to 10 feet. $8 to $15 per sq ft installed. Driveways need expansion joints at the street and garage transitions.

Stamped or decorative: 4+ inches with integral color and pattern stamping. $12 to $20+ per sq ft installed. Stamping adds $3 to $8 per sq ft in labor for the pattern work and coloring.

Regional Price Variation

Ready-mix concrete prices vary by 15% to 30% across North America. The Southeast and Midwest are typically at the low end ($130 to $150 per yard), while the Northeast, West Coast, and remote areas run $155 to $190 per yard. Concrete prices also spike during the spring and summer construction season. Ordering in early spring or late fall (in regions with mild winters) can save 5% to 10% per yard.

Calculate Your Exact Materials

Concrete is not a material where you want to guess. Under-ordering means a cold joint (the visible line where two separate pours meet), and over-ordering wastes money. Use our concrete calculator to determine the exact number of cubic yards for your slab dimensions and thickness. The calculator accounts for the 5% to 10% waste factor you should build into your order.

Frequently Asked Questions

How much does a 20x20 concrete slab cost? +
A 20x20 concrete slab (400 sq ft) at 4 inches thick costs $1,200 to $2,400 for materials (about 5 cubic yards of ready-mix concrete at $140 to $160 per yard, plus forms, rebar, and gravel base) or $2,400 to $5,200 professionally installed. Most homeowners pay $3,000 to $4,000 for a standard 20x20 slab with basic finishing.
Is it cheaper to pour concrete yourself? +
DIY concrete saves 40% to 60% on labor, but it is only practical for small slabs (under 100 sq ft) where you can use bag mix. Anything larger requires ready-mix delivery, and you need to be ready to pour, level, and finish the entire load before it sets — typically within 60 to 90 minutes. For slabs over 200 sq ft, hiring a crew is strongly recommended unless you have concrete experience. A botched pour cannot be easily fixed.
How thick should a concrete slab be? +
Standard thickness depends on the use: 4 inches for patios, walkways, and shed pads; 5 to 6 inches for garage floors and light vehicle traffic; 6 to 8 inches for driveways or areas supporting heavy equipment. Going from 4 to 6 inches adds roughly 50% more concrete (and cost), so do not over-spec unless the load requires it. Every inch of unnecessary thickness is wasted money.
What is included in a concrete slab quote? +
A complete contractor quote should include: site preparation and excavation, 4 to 6 inches of compacted gravel sub-base, formwork, rebar or wire mesh reinforcement, concrete delivery and placement, finishing (broom, smooth, or stamped), and curing compound. Ask specifically about excavation, haul-away of soil, and gravel base — some contractors quote only the pour and finishing, leaving site prep as an extra charge.
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