Defects per Million (DPMO) Calculator
Express a defect rate on a scale that can be compared across processes of different complexity.
DPMO
2,604 DPMO
- Defects per opportunity
- 0.002604
- Total opportunities
- 9,600
- Process yield
- 99.7396%
- Sigma level (1.5σ shift convention)
- 4.29
Calculated from the values you entered. Formula version 1; last reviewed 2026-09-15.
What this calculator does
Defects divided by total defect opportunities, scaled to a million opportunities. Direct calculation from counts. The sigma level shown alongside uses the conventional 1.5 sigma shift, and the page says so.
Inputs and what they mean
- Defects found
- — number value.
- Units inspected
- — number value.
- Opportunities per unit
- — Distinct ways one unit can be defective..
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
DPMO = (Defects ÷ (Units × Opportunities per unit)) × 1,000,000
Worked example
25 defects across 1,200 units with 8 opportunities each
A defect rate expressed per million opportunities.
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
Results depend entirely on the figures you enter and are rounded for display. They are for general information and education, not professional advice.
Reference: ASQ — Process capability and defect rate measures
Last reviewed:
Common questions
Formula, source and verification
Defects divided by total defect opportunities, scaled to a million opportunities.
The question it answers: How do we compare defect levels between a simple part and a complex assembly?
The formula
DPMO = (Defects ÷ (Units × Opportunities per unit)) × 1,000,000
- D — Defects
- (count). Total defects found, not defective units.
- U — Units
- (count). Units inspected.
- O — Opportunities per unit
- (count). Distinct ways one unit can be defective.
Units: Counts in; defects per million opportunities 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
Direct calculation from counts. The sigma level shown alongside uses the conventional 1.5 sigma shift, and the page says so.
Assumptions built into the result
- Statistical: Opportunities per unit have been defined consistently for the process.
Figures this calculator will never guess for you
- No target or benchmark DPMO is implied.
Limitations
- Comparisons between processes are only meaningful when opportunities are counted the same way.
Source and version
- Standard or reference
- Defects per million opportunities — ASQ (ASQ quality resources, defect rate measures.)
- Published source
- ASQ — 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.
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