Understanding First Pass Yield
How we calculate. FPY % = units passing first time ÷ units entering × 100. See our methodology and accuracy policy .
Real-world scenario: A typical First Pass Yield case uses first-pass passes 920 and units entering 1000. Enter the same figures below to reproduce the worked path.
What is First Pass Yield?
A quality-flow KPI stronger than final yield when rework hides problems. Rolled throughput yield multiplies FPY across steps.
- No rework credit on first pass
- Entering count = process starts
- Pairs with scrap and quality rate
The Formula
Worked Example
Common Use Cases
- Lean quality: right-first-time
- Cell design: rework loops
- Supplier scorecards: incoming FPY
Pro Tips
- Don’t count rework as first pass
- Map each process step
- Watch inspection gate changes
| Scenario | When to use |
|---|---|
| Percent of a number | Finding a part of a whole (tax, tip, score) |
| Percent change | Comparing old vs new values |
Limitations: First Pass Yield results are educational manufacturing and lean/TPM planning aids—not process-safety, quality-system, or financial advice. Confirm definitions with your MES/SCADA and quality policies.
Common mistakes
- Swapping part and whole: The denominator must be the full total, not a subset.
- Rounding too early: Carry extra decimal places through multi-step work before rounding the final percent.
- Mixing percent and decimal forms: Enter rates in the format the calculator labels expect.
The worked example for first pass yield was verified with the calculator form on this page—enter the same values to confirm the result.
When to use this calculator
- Use this page when your wording matches first pass yield and the form labels on screen.
- Use percent of a number for “what is X% of Y?” problems.
- Use number is what percent when you know part and whole and need the percent.
Still unsure about first pass yield? Start with the quick answer above, then open the linked calculator that matches your wording.
❓ Frequently Asked Questions
How do I use this first pass yield calculator?
For first pass yield, enter the values labeled on the form, then press Calculate. Compare the result to the worked example on this page.
What formula does this page use?
See the quick answer and formula box above for first pass yield—the same percentage calculator expression is applied to your inputs.
What if my result looks wrong?
When checking first pass yield, re-check part vs whole (or rate vs base), rounding, and whether percents were entered as 25 rather than 0.25 when the form expects percents.
Authoritative References
For OEE and manufacturing KPI definitions, consult: