Construction Tool
Concrete Volume Calculator
Calculate the exact volume of concrete needed for your project. Choose between slabs, square footings, or circular columns, and easily estimate the number of premixed bags required.
How much concrete do I need?
Calculating concrete volume relies on simple geometric formulas depending on the shape of your pour.
- Slabs and Footings: Length x Width x Depth
- Columns and Holes: Pi x Radius² x Depth
How many bags of concrete make a yard?
A single cubic yard of concrete is equal to 27 cubic feet. Here is a quick reference for standard bag sizes:
- It takes 45 bags (80 lb) to make 1 cubic yard.
- It takes 60 bags (60 lb) to make 1 cubic yard.
- It takes 90 bags (40 lb) to make 1 cubic yard.
Our calculator automatically includes a standard 5% waste factor for pre-mixed bags. It is always wise to buy an extra bag or two since uneven subgrades, spills, and mixing can reduce your true yield.
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