Concrete Calculator
Estimate concrete for slabs, patios, sidewalks, driveways, footings, and round columns. Enter your project dimensions to calculate cubic feet, cubic yards, ready-mix quantity, bag count, waste factor, and estimated material cost.
How to Use the Concrete Calculator
- Choose the project type: slab, footing, or round column.
- Enter the project dimensions.
- Select a concrete bag size or enter a custom bag yield.
- Add a waste or overage factor. Ten percent is a common planning estimate.
- Enter optional price information to estimate cost.
Common Concrete Thicknesses
| Project Type | Common Thickness | Notes |
|---|---|---|
| Sidewalk | 4 inches | Common for pedestrian traffic |
| Patio | 4 inches | May vary by soil and intended use |
| Driveway | 4–6 inches | Thicker slabs may be needed for heavier vehicles |
| Garage slab | 4–6 inches | Confirm local code and reinforcement needs |
| Footing | Varies | Depends on structure, frost depth, soil, and code |
Concrete Estimating Tips
Smart Buying Tips
- Round up concrete orders to avoid running short during the pour.
- Use ready-mix delivery for larger projects when bag mixing becomes unrealistic.
- Check the exact bag yield on the product label before buying.
- Account for uneven subgrade, form variations, and spillage.
Common Mistakes
- Forgetting to convert inches into feet before calculating volume.
- Not adding waste or overage.
- Underestimating the labor required for bag mixing.
- Ignoring reinforcement, base gravel, form boards, and finishing tools.
Related Calculators
Concrete Calculator Guide
This concrete calculator helps estimate concrete volume for common residential and DIY projects. It calculates cubic feet and cubic yards from your project dimensions, then estimates the number of concrete bags required based on bag yield.
For larger projects, cubic yards are usually the most important number because ready-mix concrete is commonly ordered by the cubic yard. For small projects, bag count may be more useful.
Ready-Mix vs. Bagged Concrete
Bagged concrete is convenient for small repairs, post holes, small pads, and isolated pours. Ready-mix delivery is usually more practical for larger slabs, driveways, patios, and projects where consistent mixing matters.