Concrete Bags Calculator
Estimate concrete volume and convert it to bags (80/60/50/40 lb or custom yield).
Quick guide
- Estimate concrete volume from area and thickness (slabs, pads, small pours).
- Choose a bag size (80/60/50/40 lb) to convert volume to bags and round up.
- Add a small buffer for spillage and uneven subgrade (often 5-10%).
Concrete Bags Calculator
Estimate concrete volume and convert it to bags (80/60/50/40 lb or custom yield).
Units
Results
- Estimated cubic yards
- 1.63
- Cubic feet
- 44
- Estimated bags
- 74
Note: bag yield varies by product and water. For best accuracy, use the yield shown on your bag label.
How to estimate concrete bags
- Measure total area (length x width) and choose the finished thickness.
- Convert to cubic feet and then divide by the bag yield (cubic feet per bag).
- Round up to whole bags and consider mixing losses and waste.
Assumptions to double-check
- Bag yield depends on product and mix water; use the bag label if possible.
- Thickness is average thickness across the pour—high/low spots change volume.
- For larger jobs, ready-mix may be cheaper and more consistent than bagged mix.
Buying tips
- Check the bag label for yield and recommended water—brands differ.
- Buy extra if you need continuous placement (you don't want to run short mid-pour).
- Plan mixing time, help, and tools—bagged concrete is labor-intensive.
Last updated: Dec 2025
FAQ
How many 80 lb bags of concrete do I need?
Enter your area and thickness, then choose 80 lb bags. The calculator converts volume to bags and rounds up.
Why do different bag sizes give different results?
Different bag weights have different yields (cubic feet per bag). Always confirm yield on the product label.
Should I add waste?
Yes. Spillage, uneven subgrade, and mixing losses can add up. 5-10% is a common buffer.
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Disclaimer
Results are estimates for informational purposes only. Always verify measurements and product specifications.