Concrete Calculator
Estimate how much concrete you need for slabs, footings, columns, stairs, and other projects. Get cubic yards, pre-mix bags, and an optional cost estimate.
Results
- Concrete needed
- 1.23 cu yd
- With 10% waste
- 1.36 cu yd
- Cubic feet
- 33.33 cu ft
- Cubic meters
- 0.94 m³
- 80 lb bags
- 62 bags
- 60 lb bags
- 82 bags
- 40 lb bags
- 123 bags
Estimates only. Round up and buy a little extra to account for waste, spills, and breakage.
Formula
Volume (cu ft) = area × thickness ÷ 12. Cubic yards = cu ft ÷ 27. Bags ≈ cu ft ÷ yield per bag.
Frequently asked questions
- How many bags of concrete are in a cubic yard?
- About 45 bags of 80 lb, 60 bags of 60 lb, or 90 bags of 40 lb pre-mix concrete equal one cubic yard.
- How much extra concrete should I order?
- Order 5–10% extra for spillage and uneven subgrade. For complex pours, add up to 15%.
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