Smoking Pack-Year Calculator
Pack-years measure how much you have smoked over your lifetime. Doctors use them to judge the risk of lung cancer, COPD and heart disease.
The Smoking Pack-Year Calculator is being built
This free calculator will appear here shortly. Meanwhile, the formula and ranges below show exactly how it works.
- Cigarettes per day
- Years smoked
- Years since quitting (optional)
- Pack-years
- Screening eligibility note
About the Smoking Pack-Year Calculator
It is never too late to quit. Risk starts falling within months of stopping and keeps falling for years.
Formula explained
Pack-years = (cigarettes per day ÷ 20) × years smoked
Example: 10 cigarettes a day for 30 years = 0.5 × 30 = 15 pack-years. Adults aged 50–80 with 20 or more pack-years who smoke now or quit within 15 years are advised yearly low-dose CT lung cancer screening (USPSTF 2021).
Frequently asked questions
Do bidis count?
Bidis are at least as harmful as cigarettes. Doctors often count them like cigarettes when estimating smoking history.
Where can I get help to quit?
Talk to your doctor about nicotine replacement and counselling. In India, the National Tobacco Quitline is 1800-112-356.
Medical disclaimer: These tools give general information and estimates only. They are not a diagnosis and do not replace advice from a qualified doctor. Always talk to your doctor about your results, and seek urgent medical help in an emergency.