Bag weight alone does not mathematically determine yield. Use the product data sheet or package label and edit the yield field when needed.
01 / Formula
How this is calculated
Bags = round up(required cubic feet × (1 + waste %) ÷ cubic feet yielded per bag)02 / Assumptions
What the estimate assumes
- ✓Yield means finished mixed volume per bag.
- ✓The default examples reflect cited QUIKRETE Concrete Mix data and may not match another product.
- ✓Bags are rounded up because partial bags are not a reliable purchase unit.
03 / Worked example
See the math in context
Twenty cubic feet divided by an example 0.60 cu ft yield equals 33.34, so the purchase estimate is 34 bags before any added waste.
04 / Guidance
Check the exact mix
High-strength, fast-setting, lightweight, repair, and specialty mixes can differ. Match the calculator to the yield for the exact product and bag size being purchased.
Questions
Frequently asked
Should I order exactly the calculated amount?+
Usually no. Excavation variation, form dimensions, spillage, and uneven subgrade can increase actual volume. Use the editable waste allowance and discuss minimum loads and order increments with the supplier.
How many cubic feet are in a cubic yard?+
There are exactly 27 cubic feet in one cubic yard. Divide cubic feet by 27 to convert to cubic yards.
Does this replace a structural design?+
No. These tools estimate material quantity only. A qualified professional and applicable plans, codes, site conditions, reinforcement requirements, and manufacturer instructions govern the project.
Sources