Scope and assumptions
Illustrative yield/scrap math; real factories use first-pass and rolled throughput yield. Not engineering advice.
A factory line makes 1,000 units and 950 of them are good — the yield is the one number the floor lives and dies by. It's a single division, good over total, and the scrap rate is just whatever that leaves behind. Simple math, but it's the line between a profitable run and a loss.
The formulas
Yield % = (Good Units ÷ Total Units) × 100 Scrap % = 100 − Yield %
Worked examples
| Total | Good | Yield % | Scrap % |
|---|---|---|---|
| 1,000 | 950 | 950/1000 × 100 = 95% | 5% |
| 500 | 480 | 96% | 4% |
| 2,000 | 1,900 | 95% | 5% |
| 800 | 760 | 95% | 5% |
Why yield percent matters
A 95% yield means 5% of material and labor is wasted. Across high volume, small scrap-percent improvements save large cost. Going from 95% to 97% yield on 1,000 units saves 20 good units' worth of scrap every run.
First-pass vs rolled yield
This simple yield counts all good units eventually. First-pass yield excludes reworked units and is usually lower, a unit fixed on the second try still counts as good in simple yield but not in first-pass. Don't confuse the two when benchmarking.
The cost of scrap
Scrap % isn't just lost units, it's lost raw material, machine hours, and energy, plus the cost of rework labor. A 5% scrap rate on a $10 unit line making 10,000/day is $5,000/day of waste. The percent translates directly to dollars.
Yield Percentages That Mask Defects
Wrong base (divide good by total produced, not by good); ignoring rework (reworked units may inflate simple yield); mixing scrap and defect rate (scrap % is of total units; defect rate may count multiple defects per unit); skipping × 100 (the ratio is a decimal until scaled); comparing first-pass to simple yield (they measure different things); and ignoring the volume multiplier (a small percent is big money at scale).
Related industry guides
For the rest of the industry cluster, start at the hub: Percentage in Finance Interest. Adjacent: Percentage in Construction Material and Recipe Scaling Percentage.
FAQ
What's rolled throughput yield vs simple yield? Simple yield counts good eventually; rolled throughput multiplies each process step's yield, so a line of five 95% steps has ~77% rolled yield — much lower than 95%.
Can yield exceed 100%? No — good units can't exceed total produced, so yield tops at 100% (only if zero scrap).
How do I use yield percent to set a target? Benchmark by process; 95% may be excellent in complex assembly but poor in simple molding. Set targets per line, not one global number.
Does scrap percent include rework? Simple yield may count reworked units as good; first-pass yield excludes them. Decide which you report — they differ.
How does yield translate to cost savings? Each point of scrap lost is material + machine time + energy; on high volume, a 2-point yield gain is large daily dollars.
Sources: Investopedia, Manufacturing yield.
Disclaimer: Illustrative. Real production uses first-pass and rolled-throughput yield; consult quality engineering for plant metrics. Informational only.
Sources and references
- Investopedia — Manufacturing yieldhttps://www.investopedia.com/terms/y/yield.asp
Maintenance and corrections
The named author or publishing brand is responsible for this article. Worked examples are illustrative, not user testimonials, professional advice or approval by the institutions cited. Maintenance responsibility and review methods · Report an error