How to Use Smoking Severity Index
The Smoking Severity Index is a weighted habit-intensity score that combines amount, duration, and nicotine strength. This index intentionally combines intensity, duration, and nicotine strength, so it behaves differently from a simple cigarettes-per-day count.
Enter cigarettes per day, years of smoking, and nicotine milligrams per cigarette. Use an average day for cigarette count, total years of regular smoking, and the nicotine amount listed or estimated for one cigarette.
The calculator shows the normalized index out of 100, the raw weighted value, and a low, medium, or high severity band. All three values must be positive for a severity index. The final score is normalized to 100 so very large raw values do not overflow the display.
Formula & Theory - Smoking Severity Index
The Smoking Severity Index uses this formula or scoring rule:
Index = min(100, Cigarettes per day × Smoking years × Nicotine mg / 10)This is a custom educational index rather than a validated clinical scale. It is useful for comparing scenarios, but it does not replace pack-years, dependence testing, or medical risk assessment.
The index is a custom comparison score. It can show direction and relative change, but it should not be treated as a validated disease-risk calculator.
Use Cases for Smoking Severity Index
The Smoking Severity Index is especially useful for:
- showing how smoking duration changes cumulative severity
- comparing low- and high-nicotine products
- creating a simple progress baseline before quitting
- health education about dose and duration
Use it to compare scenarios such as fewer cigarettes, lower nicotine strength, or shorter duration. For clinical screening, pair it with established tobacco-use history tools.