Worked example
How Much Concrete for a 10x10 Slab?
This example uses a 10 ft by 10 ft slab at 4 in thick and shows volume plus bag count using your selected bag yield.
Concrete
Calculator inputs
Concrete Slab Calculator Results
Results update in your browser as you edit inputs.
Enter project dimensions to calculate material quantity.
Inputs used in this example
- Slab size: 10 ft by 10 ft.
- Thickness: 4 inches.
- Bag yield: 0.6 cubic feet per bag.
- Waste factor: 5%.
Expected output
The calculator estimates 33.33 cubic feet before waste, 35 cubic feet after 5% waste, and about 59 bags at 0.6 cubic feet per bag.
Formula explanation
- Convert 4 inches to 0.333 feet.
- Multiply length x width x thickness to get cubic feet.
- Divide cubic feet by 27 to get cubic yards.
- Divide waste-adjusted cubic feet by bag yield for bag count.
Main calculator
Use the full Concrete Slab Calculator to change dimensions, waste factor, and optional user-entered unit price.
FAQ
Can this replace a ready-mix quote?
No. It estimates material quantity only and does not provide live prices or contractor quotes.
Where do I find bag yield?
Use the yield printed on the concrete bag you plan to buy.