First Pass Yield Calculator
Find the share of units that passed with no rework of any kind.
In short
Find the share of units that passed with no rework of any kind.
Formula: FPY = (Units passing first time ÷ Units started) × 100
What this calculator does
One division expressed as a percentage, with the complement shown as the share not passing first time.
Use it to turn Units started, Units passing first time into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this professional & industry calculation.
Inputs and what they mean
- Units started
- — number value.
- Units passing first time
- — Units that met specification with no rework, repair, retest or reinspection..
How to use it
- Enter your own figures — the calculator never fills in a rate, price or benchmark for you.
- Press Calculate to see the result.
- Read the formula, variables, assumptions and source below the result before you rely on it.
Formula
FPY = (Units passing first time ÷ Units started) × 100.
Inputs used: Units started, Units passing first time.
Edge handling: Units started is required.; Units started cannot be negative.; Units started must be no more than 1000000000000.; Units passing first time is required.; Units passing first time cannot be negative..
Worked example
462 of 500 units right first time
- Start with Units started: 500, Units passing first time: 462.
- Apply the method: FPY = (Units passing first time ÷ Units started) × 100.
- Units that needed rework are excluded from the pass count.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Inputs outside the supported range are rejected rather than forced into a result.
- The result depends on the values you enter for this first pass yield calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Reference: American Society for Quality — Process capability and defect rate measures
Last reviewed:
Common questions
Where does this formula come from?
ASQ quality resources, yield measures: first pass yield excludes reworked units from the pass count. See the source link on this page.
What kind of calculation is this?
The proportion of units that passed without rework, repair, retest or reinspection. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
What are its limits?
A final yield that counts reworked units as passes will read higher than first pass yield; the two are different measures. Arithmetic over the counts entered — it cannot tell whether the inspection behind them was complete or consistent.
How do I use the First Pass Yield Calculator?
Enter the required values for Units started, Units passing first time. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the First Pass Yield Calculator use?
FPY = (Units passing first time ÷ Units started) × 100 The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
Can the First Pass Yield Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Formula, source and verification
The proportion of units that passed without rework, repair, retest or reinspection.
The question it answers: How much of our output is right first time, and how much survives every step?
The formula
FPY = (Units passing first time ÷ Units started) × 100
- P — Units passing first time
- (count). Units that met specification with no rework.
- S — Units started
- (count). Units entering the step or process.
Units: Counts in; percentage out.
What kind of calculation this is
Deterministic formula. The same inputs always give the same answer. The maths is fixed and does not depend on judgement.
Method
One division expressed as a percentage, with the complement shown as the share not passing first time.
Assumptions built into the result
- Mathematical: Reworked, repaired, retested and reinspected units are excluded from the pass count.
Figures this calculator will never guess for you
- No benchmark, target or 'world class' value is supplied or implied; the result describes only the figures entered.
- No rolled yield across steps is inferred from a single step's yield.
Limitations
- A final yield that counts reworked units as passes will read higher than first pass yield; the two are different measures.
- Arithmetic over the counts entered — it cannot tell whether the inspection behind them was complete or consistent.
Source and version
- Standard or reference
- First pass yield — ASQ (ASQ quality resources, yield measures: first pass yield excludes reworked units from the pass count.)
- Published source
- American Society for Quality — Quality resources
- Formula version
- Version 1
- Verification
- Reviewed against the cited source on
- How much weight the source carries
- Standards or government
- Applies to
- Currency
- The result is a ratio or index, so it does not depend on currency.
Cite this page
Free Calculator. (2026, September 16). First Pass Yield Calculator. https://freecalculator.tech/tools/first-pass-yield-calculator
"First Pass Yield Calculator." Free Calculator, 16 Sept. 2026, https://freecalculator.tech/tools/first-pass-yield-calculator.
First Pass Yield Calculator — Free Calculator, https://freecalculator.tech/tools/first-pass-yield-calculator
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