Concrete Calculator

How much does a concrete slab cost?

The national average cost to pour a concrete slab is $4–$8 per square foot for a basic 4-inch slab, including materials and labor. A typical 10 ft × 10 ft patio slab therefore costs roughly $400–$800, while driveways and foundations run into the thousands.

Concrete cost by project

• Patio slab (10 × 10 ft): $400–$800
• Driveway (12 × 30 ft): $1,500–$4,000
• Foundation (1,200 sq ft home): $8,000–$20,000
• Sidewalk / path: $6–$12 per linear foot

Factors that affect concrete cost

• Thickness: 4 inches is standard for patios and sidewalks; driveways need 4–6 inches; foundations 8–12 inches.
• Reinforcement: wire mesh or rebar adds strength and $0.50–$1 per sq ft.
• Finish: a plain broom finish is cheapest; stamped or stained concrete adds $2–$12 per sq ft.
• Labor and access: hard-to-reach sites, excavation, and old-slab removal all raise the price.
• Region: labor and delivery costs vary significantly by location.

How to calculate concrete volume

Concrete volume is length × width × depth. Convert to cubic yards (US) by dividing cubic feet by 27, or read cubic metres directly (metric).

• US: an 80 lb bag covers about 0.6 cubic feet; a 60 lb bag covers 0.45 cubic feet.
• Metric: a 25 kg bag makes about 0.013 m³; a 20 kg bag makes about 0.010 m³.
• Always add 10% extra to account for spillage and uneven ground.

DIY vs. hiring a pro

Bagged ready-mix is realistic for small DIY pours such as steps, fence posts and small pads. Anything over about 1 cubic yard is usually cheaper and faster with a concrete truck delivery, and finishing a large slab well requires experience. For most slabs, budget for a contractor.

Frequently asked questions

How many 80 lb bags of concrete do I need?

An 80 lb bag makes about 0.6 cubic feet. Divide your total cubic feet by 0.6, then add 10% for waste.

How much concrete do I need for a 10×10 slab?

A 10 ft × 10 ft × 4 in slab is about 1.23 cubic yards, or 56 eighty-pound bags.

Is 4 inches of concrete enough for a driveway?

For cars and light trucks, yes — 4 inches is the minimum. For heavier vehicles, use 5–6 inches.

How much does concrete cost per yard?

Concrete typically costs $110–$165 per cubic yard for the material alone, delivered.