🏗️ Concrete Calculator
Calculate concrete volume, bags needed, and material costs for slabs, footings, and construction projects.
Material & Cost Settings
Typical: 5-15%
Concrete Calculator Features
🏗️ Multiple Shapes
Calculate concrete for slabs, footings, columns, and stairs. Support for square, rectangular, and round shapes.
💰 Cost Estimation
Estimate material costs with customizable bag sizes, prices, and waste factors for accurate budgeting.
📐 Unit Flexibility
Work with feet, inches, meters, or centimeters. Get results in cubic yards, feet, meters, and bag counts.
Concrete Calculator FAQ
How much concrete do I need for a 10x10 slab?
For a 10x10 foot slab that's 4 inches thick, you need approximately 1.23 cubic yards of concrete, which equals about 37 bags of 60-pound concrete mix.
What's the difference between 40, 60, and 80 lb bags?
The numbers refer to the weight of each bag. Heavier bags cover more area but are harder to handle. 60 lb bags are most common for DIY projects, covering about 0.45 cubic feet each.
Why add a waste factor?
A waste factor accounts for spillage, over-excavation, and irregular surfaces. Typical waste factors range from 5-15%, with 10% being standard for most projects.
How thick should my concrete slab be?
Typical thicknesses: 4" for walkways and patios, 6" for driveways and light vehicle areas, 8" for heavy vehicle areas. Always check local building codes.
When to Use This Calculator
Use this when planning a concrete pour for a driveway, patio, foundation, or sidewalk and you need to calculate how many cubic yards or cubic meters of concrete to order from a supplier.
Common Mistakes to Avoid
- Not adding a 10% waste factor — always order slightly more than calculated to account for spillage and uneven ground.
- Mixing up depth units — most residential concrete is 4 inches deep, not 4 feet; double-check your depth entry.
- Forgetting to account for forms or reinforcement — steel rebar and wood forms slightly reduce the total concrete volume needed.