What is the difference between RTY and simple yield?

Simple (rolled) yield counts only units that exit the line, including those that were reworked. RTY counts only units that passed every step without any defect or rework. RTY is always ≤ simple yield and reveals hidden rework cost.

How do I handle reworked units when calculating FPY?

Reworked units count as defects in the step where the defect was detected, even if they are repaired and eventually pass. FPY = (units in − defects at step) ÷ units in.

What sigma level corresponds to a given RTY?

Convert RTY to DPMO = (1 − RTY) × 1,000,000, then determine the sigma level (including the standard 1.5σ shift). For example, RTY = 99.99966% → DPMO ≈ 3.4 → 6.0σ. This calculator estimates sigma using an inverse normal CDF calculation with a 1.5-sigma shift.

Can RTY exceed the yield of any individual step?

No. RTY is a product of all step FPYs, so it is always less than or equal to the lowest individual step FPY.

What does normalized yield tell me?

Normalized yield (RTY^(1/n)) is the geometric mean step yield — the hypothetical uniform per-step FPY that would produce the same RTY. It lets you compare lines with different numbers of steps on equal footing.

Rolled Throughput Yield Calculator

Calculate RTY — the probability a unit passes every manufacturing step without defect or rework.

#	Step Name (optional)	Units In	Defects Found	FPY

Summary

Rolled Throughput Yield (RTY) multiplies the first-pass yield of each process step to show the true probability that a unit exits the entire line without ever being defective or reworked. A single step at 95% FPY looks fine; five such steps chained together yield only 77.4% RTY, exposing hidden quality cost invisible to simple scrap-rate views.

How it works

Enter units entering and defects found at each process step.
First-Pass Yield (FPY) for each step = (units in − defects) ÷ units in.
RTY = FPY₁ × FPY₂ × ... × FPYₙ — the product of all step yields.
Normalized yield = RTY^(1/n), the geometric mean step yield.
Sigma level is estimated from RTY using the standard DPMO conversion.

Use cases

Identify which process steps drag down overall line yield.
Compare RTY before and after a process improvement to quantify gains.
Set realistic quality targets when designing multi-step assembly lines.
Communicate hidden rework cost to management using a single metric.
Support DMAIC projects by baselining RTY at the Measure phase.

Frequently Asked Questions

Last updated: 2026-06-15 · Reviewed by Nham Vu

Rolled Throughput Yield Calculator

Use the Rolled Throughput Yield Calculator

First-Pass Yield by Step

Summary

How it works

Use cases

Frequently Asked Questions