Measure the pour area
Use finished dimensions for length and width. For irregular areas, split the project into smaller rectangles.
Concrete calculator
Concrete Calculator
Estimate concrete yards, cubic feet, cubic meters, and bag counts for common slab pours.
Estimated concrete needed1.36 yd³ with 10% waste
- Cubic feet
- 33.33 ft³
- Cubic meters
- 0.94 m³
- 80 lb bags
- 56
- 60 lb bags
- 75
- 40 lb bags
- 112
How to use it
Enter slab thickness
Most patios and walkways use 4 inches. Driveways and load-bearing work may need more.
Order with waste
Use the 10% waste recommendation to cover spillage, uneven subgrade, and small measurement errors.
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FAQ
Concrete estimating questions
How do I calculate concrete yards?
Multiply length by width by thickness in feet, then divide cubic feet by 27 to convert to cubic yards.
Should I order extra concrete?
Most small pours should include about 10% waste for uneven subgrade, spillage, and measurement variation.
How many 80 lb bags are in a cubic yard?
An 80 lb bag yields about 0.6 cubic feet, so one cubic yard takes about 45 bags before waste.