Concrete Calculator
Calculate the volume and weight of concrete needed for your project. Includes slabs, footings, columns and more.
Slabs & Footings
Columns & Round Footings
Circular Slabs & Tubes
Curb & Gutter
Stairs
Dimensions
Concrete Options
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Additional concrete to account for spillage and settling
Dimensions
Concrete Options
%
Dimensions
Concrete Options
%
Dimensions
Concrete Options
%
Dimensions
Concrete Options
%
What is a Concrete Calculator?
The Concrete Calculator estimates the volume and weight of concrete necessary to cover a given area. Purchasing slightly more concrete than the estimated result can reduce the probability of having insufficient concrete.
How Concrete Volume is Calculated
- For Slabs, Footings & Walls: Length × Width × Thickness
- For Columns & Round Footings: π × (Diameter/2)² × Height
- For Circular Slabs & Tubes: π × [(Outer Diameter/2)² – (Inner Diameter/2)²] × Height
- For Curb & Gutter: Combined cross-sectional area × Length
- For Stairs: Sum of individual step volumes plus platform volume
Understanding Concrete Materials
Concrete is a composite material consisting of fine and coarse aggregate bonded with a fluid cement that hardens over time. The most common form of concrete is Portland cement concrete, which consists of mineral aggregate (generally gravel and sand), Portland cement and water.
Tips for Concrete Projects
- Always add a waste factor of 5-10% to your calculations
- For large projects, consider ordering slightly more than calculated
- Standard concrete mix has a density of approximately 150 lb/ft³ (2,400 kg/m³)
- One cubic yard of concrete weighs about 4,050 pounds (2 tons)
- Allow adequate curing time (typically 28 days for full strength)
Common Concrete Mix Ratios
| Strength | Cement | Sand | Gravel |
|---|---|---|---|
| High (4000+ psi) | 1 | 2 | 3 |
| Medium (3000 psi) | 1 | 2.5 | 3.5 |
| Low (2000 psi) | 1 | 3 | 4 |