DPMO / Sigma Level Calculator
Calculate defects per million opportunities (DPMO) and convert to Six Sigma process level
DPMO / Sigma Level Calculator
Complete Guide to DPMO & Sigma Levels
What is DPMO?
DPMO (Defects Per Million Opportunities) normalizes defect rates across different products and processes by accounting for the number of opportunities for a defect in each unit. It enables fair comparison between a simple product with 2 features and a complex one with 200.
DPMO = (Defects / (Units × Opportunities)) × 10⁶Key Metrics
- DPU — Defects Per Unit = Total Defects / Total Units
- DPO — Defects Per Opportunity = Defects / (Units × Opps)
- DPMO — DPO × 1,000,000
- Yield — (1 - DPO) × 100%
- Sigma — Z-score corresponding to yield + 1.5σ shift
Six Sigma Reference Table
| Sigma Level | DPMO | Yield | Defect Rate |
|---|---|---|---|
| 1σ | 691,462 | 30.85% | 69.15% |
| 2σ | 308,538 | 69.15% | 30.85% |
| 3σ | 66,807 | 93.32% | 6.68% |
| 4σ | 6,210 | 99.38% | 0.62% |
| 5σ | 233 | 99.977% | 0.023% |
| 6σ | 3.4 | 99.99966% | 0.00034% |
FAQ
What is the 1.5 sigma shift?
Motorola’s Six Sigma methodology accounts for a 1.5σ long-term shift in process mean. A "6 sigma" process has 3.4 DPMO, which corresponds to 4.5σ on a standard normal distribution + the 1.5σ shift allowance.
How do I identify opportunities per unit?
An opportunity is any measurable characteristic that could potentially be defective. For a welded assembly with 10 welds, there are 10 opportunities per unit (assuming each weld could independently fail).