How we worked it out
Updated as you change the numbers.
- Pack-years = packs per day × years smoked (20 cigarettes = 1 pack).
Method and assumptions
The US Preventive Services Task Force (2021) recommends yearly low-dose CT screening for adults 50 to 80 with a 20 pack-year history who smoke now or quit within the past 15 years.
Questions
How many pack-years is a pack a day for 22 years?
22 pack-years.
Sources
Method and figures checked on . Every worked answer on this page is covered by an automated test. Found a mistake? Tell us.