Measure the pour area
Use finished dimensions for length and width. For irregular areas, split the project into smaller rectangles.
Concrete calculator
Concrete Slab Calculator
Calculate cubic yards and bags needed for flat concrete slabs.
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 much concrete do I need for a 10x10 slab?
A 10 by 10 foot slab at 4 inches thick needs about 1.23 cubic yards before waste.
What thickness should a concrete slab be?
Many patios, walkways, and shed pads use 4 inches. Driveways or structural slabs may require more.
Can I use bags for a slab?
Small slabs can use bagged concrete, but larger slabs usually make more sense with ready-mix delivery.