Pack Year Calculator for Cigarettes and Bidis
Enter how many cigarettes or bidis you smoke (or smoked) a day and for how many years to see your pack-years.
- Nothing you type is stored
- Free
- No signup
Pack-years
7.5
Under 20 pack-years- Smoking index (sticks/day × years)
- 150
- Total sticks smoked
- 54.79 thousand
An estimate for general information, not medical advice.
Quitting lowers risk at any age. Free National Tobacco Quitline: 1800-112-356.
Show working
- (10 ÷ 20) × 15 = 7.5
How to use
- Choose cigarettes, bidis or both.
- Enter the number per day and the years smoked.
- Read your pack-years and smoking index.
Good to know
Pack-years = (cigarettes per day ÷ 20) × years smoked. One pack-year is 20 cigarettes a day for a year. 10 a day for 15 years = 7.5 pack-years. Doctors use pack-years to judge lung and heart risk, and some countries use 20 or more pack-years (with age 50–80) to offer lung-cancer screening.
Bidis: there is no agreed way to convert bidis to cigarettes. Here each bidi counts as one stick, the same as a cigarette. Bidis are not safer: per stick they deliver as much or more tar, nicotine and carbon monoxide, and bidi smokers have high rates of mouth, lung and throat cancer. Indian studies often use the smoking index (sticks per day × years) instead, also shown.
Risk falls after quitting at any age. India's free National Tobacco Quitline is 1800-112-356. If you have cough, breathlessness, chest pain or blood in sputum, see a doctor whatever your pack-years.
Questions
How do I calculate pack-years?
Divide the cigarettes you smoke a day by 20 and multiply by the years you have smoked. 20 a day for 10 years = 10 pack-years.
How are bidis counted?
Each bidi is counted as one stick, like a cigarette. There is no official conversion, and bidis are at least as harmful.
What does 20 pack-years mean?
It is the level some guidelines use to offer lung-cancer screening to people aged 50–80. Ask a doctor whether screening is right for you.
I quit years ago. Should I still count?
Yes, count the years you smoked. Your risk is lower than if you had continued and keeps falling over time.
Where can I get help to quit?
Call the National Tobacco Quitline on 1800-112-356 (free) or ask at your nearest government hospital's tobacco cessation centre.