ToolsCalculators
Pack-years (smoking history)
Cumulative cigarette exposure in pack-years.
Pack-years (smoking history)
Cigarettes per day
cig/day
Years smoked
years
Complete the fields above to see the result.
When to use
- Quantifying lifetime smoking exposure for lung-cancer screening and risk assessment.
Formula
Pack-years = (cigarettes per day ÷ 20) × years smoked.