Pack Years Calculator

Pack-years put a rate and a duration into one number: packs a day multiplied by years smoked, where one pack is twenty cigarettes unless you change it. Enter either cigarettes a day or packs a day with the number of years, or list several periods at different rates and the tool adds their pack-years together. It shows the division and multiplication it used, the total cigarettes, and which period contributed most. Pack-years are an exposure measure used alongside age and time since quitting in screening criteria; no risk or probability of illness is calculated here.

Calculator Type
Counted As
Twenty is the standard pack and the usual assumption. Change it only if yours differs.
Leave at zero if still smoking.
Widget
One period per entry, separated by semicolons. Either "cigarettes per day, years" or "cigarettes per day, start age, end age". Example: 20, 10; 30, 18, 26 means twenty a day for ten years, then thirty a day from age 18 to 26.
Leave at zero if still smoking.
Widget
Related Tools
BMI Calculator BAC Calculator Heart Disease Risk Calculator