Method / assumptions / examples
How this calculation works
The result is deterministic: the same measurements always return the same estimate. Here is the relationship and where real-world results can differ.
01
Formula
Waste % = (input − good output) ÷ input × 100
Input and output may be counts, length, area, or weight as long as both figures use the same unit and represent the same process boundary.
02
Worked example
Examples
350 units lost
Starting with 10,000 units and recording 9,650 good units gives 3.5% waste and 96.5% yield.
03
Common mistakes
What to check before using the result
- Define the process boundary before comparing jobs—for example, issued material to packed good product.
- Keep units consistent. Do not compare input weight with finished piece count.
- Separate planned setup waste from defects when you need an actionable loss breakdown.
04
FAQ
Frequently asked questions
Is waste percentage the inverse of yield?
When all input is classified as either good or waste, yes: waste percentage plus yield percentage equals 100%. Rework and work-in-process can complicate that boundary.
Can I use feet or kilograms?
Yes. Any consistent unit works. Both input and good output must use that same unit.