Building tool
Concrete Bag Calculator
Find concrete volume and the number of premix bags needed for a slab.
Runs in your browserResult
- Concrete volume
- 40 cu ft
- Cubic yards
- 1.63 yd³
- Bags needed
- 74
- Wet weight estimate
- 6,380 lb
Bag yield depends on bag size and product. Structural pours require proper reinforcement, subbase, mix, curing, and code review.
How to use this concrete bag calculator
- Measure the project, enter the dimensions in the units shown, and add the waste, spacing, coverage, or material settings that apply.
- Review the calculated totals, units, and assumptions. Check the inputs and units before relying on the result.
- Change one input at a time to compare another case, then copy or save the result you plan to use.
About this concrete bag calculator
The Concrete Bag Calculator lets you find concrete volume and the number of premix bags needed for a slab. The controls cover only the inputs needed for the result.
You can also use it to compare results after changing one input.
Example
Enter a 12 by 10 foot slab at 4 inches thick, then compare the required 60 pound and 80 pound bag counts.
Common uses
- → find concrete volume and the number of premix bags needed for a slab
- → compare results after changing one input
- → save an estimate for planning or comparison