- Enter total production. Count all units included in the production batch or reporting period.
- Enter good units. Use the count that passed the quality definition applied to this analysis.
- Add a unit value if useful. Enter 0 to omit a simple value estimate.
- Review yield loss. The main result is the percentage of total units that were not counted as good output.
- Use the value estimate carefully. Multiplying lost units by one unit value does not model rework recovery, scrap proceeds, or different defect severities.
Production Line Yield Loss Estimator
Estimate production line yield loss by comparing total units produced with units that meet the chosen good-output definition. The calculator reports both the number of lost units and the percentage of total production they represent, while also showing the corresponding yield. Quality and operations teams can use the metric to quantify how much output is being lost before attaching cost or root-cause information. It is intentionally a simple unit-based view; rework, downgrade, scrap value, and defect severity may need separate analysis if they have different operational or financial consequences.
Production and good output
units
units
USD
Result
—
Yield loss rate
Lost / non-good units—
Yield—
Optional loss value—
Lost units = Total units − Good units
Yield loss (%) = Lost units ÷ Total units × 100
Yield (%) = Good units ÷ Total units × 100
Optional loss value = Lost units × Value per unit
Good units cannot exceed total units. The optional value is a simple gross exposure estimate, not a full cost-of-quality calculation.
What the result means
The main result shows what share of total produced units failed to count as good output under the entered definition.
Distinguish scrap, rework, downgrade, and other loss categories separately when their economics or recovery paths differ.
Given: 1,000 total units, 965 good units, and optional unit value of $12.
Calculation: Lost units = 1,000 − 965 = 35. Yield loss = 35 ÷ 1,000 × 100 = 3.5%. Yield = 96.5%. Optional loss value = 35 × $12 = $420.
Result: Yield loss = 3.5%.
Interpretation: Thirty-five units, or 3.5% of the run, were not counted as good output under the chosen definition.
Should reworked units count as good units?
Use the rule that matches your reporting purpose. If reworked units eventually meet the good-output definition, you may count them as good, but track first-pass yield separately if initial quality matters.
What if good units equal total units?
Yield loss is 0% and yield is 100% for the data entered.
Can I use weight or volume instead of unit counts?
This page is designed for unit counts. For process industries measured by mass or volume, use a yield model whose numerator and denominator use the same physical quantity.
What does the optional loss value represent?
It is lost-unit count multiplied by one entered unit value. It does not automatically include labor, disposal, rework, recovery value, warranty impact, or lost capacity.
How is yield loss different from OEE quality?
They are closely related when OEE quality is defined as good units divided by total units. OEE then combines that quality factor with availability and performance, while this calculator isolates the output-loss portion.