Skip to main content

Advertisement

Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Table 1 Pack-years of smoking

From: Clinical verification of the relationship between smoking and the immune microenvironment of breast cancer

To calculate smoking pack-years:
  Divide the number of cigarettes smoked per day by 20 (the number of cigarettes in a pack)
  Then multiply by the number of years smoked
ex. 1 (70 cigarettes/day ÷ 20 cigarettes/pack) × 10 years = 35 pack-years
ex. 2 (35 cigarettes/day ÷ 20 cigarettes/pack) × 20 years = 35 pack-years
ex. 3 (20 cigarettes/day ÷ 20 cigarettes/pack) × 20 years = 20 pack-years