Concrete Bag Calculator
Estimate the number of concrete mix bags needed from project dimensions or a known concrete volume and the bag yield printed on the package.
Results
Concrete volume
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Bags required
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Use the result as a planning estimate and verify project-specific dimensions, product information and local requirements where relevant.
How it works
The calculator determines concrete volume, applies the extra allowance, divides by the stated yield per bag and rounds up to a whole bag.
bags = ceil(adjusted concrete volume ÷ yield per bag)Worked example
A 6 ft × 4 ft slab at 4 in thick is 8 ft³ before extra allowance. Enter the yield printed on your chosen bag.
Limitations
- Bag yields vary by product and placement conditions; use the manufacturer’s stated yield.