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Concrete Calculator
Free Concrete Calculator: Estimate the volume of concrete in cubic yards and the number of bags needed for slabs, footings, or columns.
Inputs
Enter the required values to calculate.
Result
The calculated result will appear here.
Enter values and click calculate to see the result.
More Information
Understanding the Concrete Calculator
This calculator helps you estimate the volume of concrete you need for various projects, such as slabs, footings, and columns. It also calculates the approximate number of pre-mixed bags you'll need to buy.
How It Works
The calculator uses standard geometric formulas to find the volume of your shape. It then converts this volume into cubic yards (the standard unit for ordering ready-mix concrete) and also tells you how many bags (40, 60, or 80 lb) you would need for the job.
- Slab:
Volume = Length × Width × Thickness - Footing: Same as a slab, just different typical dimensions.
- Column (Cylinder):
Volume = π × (Radius)² × Height
Important Considerations
- Waste Factor: It's always a good practice to order 5-10% more concrete than you calculate to account for spillage, uneven subgrade, and form variations.
- Bag Yields: The number of bags is an estimate. The actual yield can vary slightly between manufacturers. Check the packaging on the bags you purchase.
For calculating the area of a surface, you can use our Area Calculator.