An 80 lb bag produces more mixed volume per bag but is heavier to lift. Compare the number of bags, handling, price per finished cubic foot, and product availability.
01 / Formula
How this is calculated
Bags = ceiling(required cubic feet ÷ stated bag yield)02 / Assumptions
What the estimate assumes
- ✓Yield examples apply to the cited QUIKRETE Concrete Mix, not every product.
- ✓The comparison excludes waste unless added to required volume.
- ✓Price is intentionally excluded because it varies by retailer and date.
03 / Worked example
See the math in context
At the cited yields, a 20-cu-ft project takes 45 of the 60 lb bags or 34 of the 80 lb bags after rounding each result up.
04 / Guidance
Compare finished volume
Bag price alone is incomplete. Divide price by stated yield to compare cost per finished cubic foot, then account for the number of lifts and mixer capacity.
05 / Guidance
Use one consistent mix
For a continuous placement, keep product type and batching consistent and follow current mixing, water, placement, and curing instructions on the product.
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