Pack-Years Calculator

Pack-Years Calculator

Pack-years are the standard way doctors quantify lifetime tobacco exposure: one pack-year equals smoking 20 cigarettes (one pack) a day for one year. It is calculated as cigarettes per day divided by 20, multiplied by the number of years smoked. A higher pack-year total is linked to greater risk of lung cancer, COPD and heart disease, and is often used to decide on lung-cancer screening. Enter your average cigarettes per day and total years smoked to see your pack-years — and remember that stopping smoking reduces risk at any age.

Information only, not a diagnosis. Pack-years help estimate risk but only a doctor can interpret it — and quitting at any point lowers risk.