Concrete & masonry
Concrete Bag Calculator
Know the project size or already have the concrete volume? Use either input method to estimate exact bag equivalents and the whole number of bags to buy.
YOUR MATERIAL ESTIMATE
A clearer quantity starts here.
Enter your measurements, check the units and calculate. Your result will include the assumptions and rounding steps.
Show calculation
THE WORKFLOW
How to use this concrete bag calculator
- Choose project dimensions or known concrete volume and confirm the units.
- Select a bag reference or enter your product’s yield per bag.
- Add optional waste and calculate; compare exact bags with whole bags to buy.
Formula & assumptions
Exact bags = order volume / yield per bag. Whole bags = round up(exact bags). Unused capacity = whole bags × yield − order volume.
Reference presets come from Concrete Mix No. 1101, not all products. Verify packaging and override the yield. Metric packaging uses your own product yield; weight alone does not determine yield.
See methodology and sources →AN ARITHMETIC EXAMPLE, NOT A RECOMMENDATION
Worked example
Example only: 1 yd³ of concrete, no extra, at a reference yield of 0.6 ft³ per bag.
- Net volume1 yd³
- Order volume1 yd³
- Order volume27 ft³
- Order volume0.765 m³
Example calculation
Extra: 0.764555 m³ × (1 + 0 / 100) = 0.764555 m³. Conversion: divide m³ by 0.764554857984 to obtain yd³.
Bags: 27 ft³ ÷ 0.6 ft³ per bag = 45; round up to 45.
Common questions
Why are bags rounded up?
Bags are purchased as whole units. The exact count is shown separately; rounding up provides enough capacity at the yield you entered.
Does every bag of the same weight have the same yield?
No. Presets are product-specific reference values. Verify your product packaging and change the yield when needed.
Estimates only. Verify measurements and manufacturer packaging/yields. Project conditions vary. This tool does not provide structural engineering advice. Read the disclaimer.