Concrete Bag Calculator — Fast & Simple
Enter your dimensions (slab or post holes) or a total volume and instantly see how many 40, 50, 60, and 80 lb bags you need. The tool also shows total weight, estimated mixing water, and optional cost. Perfect for patios, sheds, fence posts, and small pours.
Default Yields (per bag)
- 40 lb ≈ 0.30 ft³
- 50 lb ≈ 0.375 ft³
- 60 lb ≈ 0.45 ft³
- 80 lb ≈ 0.60 ft³
Quick Answers
- How many 80 lb bags in a yard? ≈ 45 bags
- How many 60 lb bags in a yard? ≈ 60 bags
- How much water per 80 lb bag? ~3–4 quarts (follow product label)
Related Tools
Planning more work? Try the Concrete Slab Calculator and Gravel Calculator.
Estimates only. Actual yields vary by brand, moisture, compaction, and site conditions.
Important Estimate Disclaimer
The results provided by this calculator are intended as general estimates only and should not be considered precise engineering measurements. Actual material requirements, costs, and quantities can vary significantly based on site conditions, local building codes, soil type, reinforcement requirements, climate exposure, and the intended use of your project.
These calculators are designed to help you plan and budget your project more effectively, but they do not replace professional advice from a qualified contractor, engineer, or building inspector. Always verify your calculations and assumptions with trained professionals before placing material orders or commencing construction.
For more information on the assumptions, formulas, and data used in these tools, see our Data Sources and Methodology pages.
Material estimates, cost figures, and volume calculations are approximate and may not reflect your actual requirements. Always double-check dimensions and project-specific needs, and consider adding a contingency allowance for waste, over-excavation, and unforeseen conditions.
If you are unsure about any aspect of your project — including structural requirements, reinforcement needs, drainage, or load-bearing capacity — consult with a licensed professional before proceeding.