Smoking habits
Smoking years
Cigarettes per day (2 - 35)
Years since quitting (0 - 46)
Hours per day in smoke-filled rooms (0 - 24)
Do you cough daily during periods of the year?
Lung cancer risk
Risk after 6 years
Risk after 16 years

HUNT Lung Cancer Risk Calculator

By Markaki M, Tsamardinos I, Langhammer A, Lagani V, Hveem K, Røe OD.
Last updated: Dec 02, 2020

Are you a smoker? Or maybe you've smoked (a bit) before? Do you wonder what are your chances of getting lung cancer after quitting smoking?

The lung cancer risk calculator will help you estimate your chance of getting lung cancer. The formula is based on scientific research of M. Markaki and her team described in 2018 in the article A Validated Clinical Risk Prediction Model for Lung Cancer in Smokers of All Ages and Exposure Types: A HUNT Study.

If the risk of lung cancer does not bother you, you can always check out the advantages of quitting smoking. It is beneficial for your health (Smoking Recovery Calculator) and your savings (Quit Smoking And Save). If that is still not convincing for you, we don't know what else is!

What percentage of smokers get lung cancer?

The obvious thing is that if you have been smoking, the lung cancer probability is higher. But what the other important elements are? The authors of the study found out that there are seven significant risk factors:

  • age,
  • pack-years,
  • smoking intensity,
  • years since smoking cessation,
  • body mass index,
  • daily cough,
  • hours of daily indoors exposure to smoke.

The answer to the question of how many smokers get lung cancer is very complicated, as it depends on so many factors.

How does lung cancer risk calculator work?

Our calculator uses the M. Markaki formulas:

Risk of developing lung cancer in 6 years:

Risk_6_years = 1.18203062 + 0.3157 * sex - 1.985 * [(age/100)^(-1) ] + 1.120 * [log⁡(pack_years) ] - 0.040 * (cig_per_day) - 0.2402 * [log(quit_years)] - 1.7024 * [log(BMI)] + 0.0807 * [log⁡(exposure)] + 0.4921 * (cough)

Risk of developing lung cancer in 16 years:

Risk_16_years = 0.1205819 * sex - 2.0020557 * [(age/100)^(-1) ] + 1.1630181 * [log⁡(pack_years) ] - 0.0295406 * (cig_per_day) - 0.2407998 * [log(quit_years)] - 1.2462656 * [log(BMI)] + 0.1663201 * [log⁡(exposure)] + 0.4059355 * (cough)


  • sex- sex-dependent coefficient: the value is equal to 1 for males and 0 for females
  • age between 21 and 86
  • cig_per_day - cigarettes smoked per day, value between 2 and 35
  • pack_years equals (cig_per_day/20) * smoking years
  • quit_years - years since quitting
  • BMI equals weight(kg) / (height(m)^2)
  • exposure hours per day spent in smoke-filled room, value between 0 and 24
  • cough answer to the question Do you cough daily during periods of the year? (yes = 1, no = 0)

Looks complicated? Use our calculator, it will estimate the lung cancer risk for you.

Research on chances of getting lung cancer after quitting smoking

The lung cancer risk calculator is based on the population study of over 65 000 people from Norway. The researchers checked 36 risk predictors and chose seven most significant to build a model. Afterward, the model was validated on other 45 000-person dataset, and it confirmed the developed formulas. The calculator may be used for screening purposes - the authors of the article proved the model's effectiveness in selecting high-risk individuals. So now, even from your home, you can estimate if you should consider CT screening and ask your doctor about it. The authors set risk thresholds at 1.75% (16 years) and 0.64% (6 years), so crossing that values may mean that you are no longer in a low-risk group.

Remember that even the best health calculator cannot substitute medical examination, advice, treatment or diagnosis. Be aware that this prediction is made on the basis of average risk for a group of people. It is possible that high-risk people won't develop lung cancer, and some with very low-risk will. Don't forget that there are other risk factors as air pollution in your place of living and genetic factors. In presented model, the age is a very significant factor, so for young and middle-aged people - even smoking a lot - the risk obtained may be really low.


The HUNT Lung Cancer Model Risk Calculator is based on scientific research and is suitable for all current and former smokers. Be aware that information provided by using this calculator is not a substitute for a medical examination or physician’s advice, diagnosis, or treatment. Your doctor is the most appropriate person to provide you with guidance on specific health issues. If you are currently ill or have symptoms, seek the help and advice of your healthcare provider.

Quitting smoking is one of the most important, beneficial health decisions you can make. Your doctor can help and guide you to quit smoking. If you use the calculator to find your personal risk, remember that the model outputs the average risk (probability) of a group of people; most high-risk individuals will not develop lung cancer, and a few low-risk individuals can eventually develop the disease. The HUNT Lung Cancer Model Risk Calculator is provided as a public service only and you use it at your own risk.

Markaki M, Tsamardinos I, Langhammer A, Lagani V, Hveem K, Røe OD.