Lung Cancer Risk Calculator

Enter your age, smoking history, and key risk factors to estimate your personal lung cancer risk. This Lung Cancer Risk Calculator uses clinically validated inputs — including pack-years, years since quitting, and family history — to output a risk category and indicate whether low-dose CT screening may be appropriate for you.

Disclaimer: This tool is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making any health-related decisions.

years

Must be between 18 and 90 years old.

Pack-years = (packs per day) × (years smoked). E.g., 1 pack/day for 20 years = 20 pack-years.

years

Enter 0 if you are a current smoker or have never smoked.

Results

Estimated Lung Cancer Risk Score

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Risk Category

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Low-Dose CT Screening Suggested

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Estimated Lifetime Risk

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Frequently Asked Questions

Who should use a lung cancer risk calculator?

This calculator is designed for adults — especially current or former smokers aged 50 and older — who want to understand their personal lung cancer risk. It is also useful for people with occupational exposures (asbestos, radon) or a family history of lung cancer. Always discuss your results with a healthcare provider.

What is a pack-year and how do I calculate it?

A pack-year equals smoking one pack of cigarettes (20 cigarettes) per day for one year. To calculate yours, multiply the number of packs smoked per day by the number of years you smoked. For example, smoking half a pack per day for 40 years equals 20 pack-years.

What are the USPSTF guidelines for lung cancer screening?

The U.S. Preventive Services Task Force (USPSTF) recommends annual low-dose CT (LDCT) screening for adults aged 50–80 who have a 20 pack-year smoking history and currently smoke or have quit within the past 15 years. Your doctor can confirm whether you meet these criteria.

Does this calculator diagnose lung cancer?

No. This tool provides a statistical risk estimate based on known population-level risk factors — it does not diagnose cancer. A high risk score means a higher probability compared to the general population, not a certainty of disease. Only a physician and appropriate diagnostic tests can confirm a diagnosis.

How does COPD affect lung cancer risk?

COPD (chronic obstructive pulmonary disease) and emphysema are independently associated with a significantly elevated lung cancer risk, even after accounting for smoking history. Studies suggest COPD patients have 2–5 times higher risk of developing lung cancer compared to smokers without COPD.

Does quitting smoking reduce my lung cancer risk?

Yes. Risk decreases progressively after quitting, but former smokers remain at elevated risk for many years. After 10–15 years of not smoking, the risk drops substantially compared to current smokers, though it never fully returns to that of someone who never smoked.

What role does radon play in lung cancer risk?

Radon is the second leading cause of lung cancer in the United States, responsible for approximately 21,000 deaths per year. It is a naturally occurring radioactive gas that can accumulate in homes and buildings. Testing your home for radon and mitigating high levels can meaningfully reduce long-term exposure risk.

Is family history an independent risk factor for lung cancer?

Yes. Having a first-degree relative (parent, sibling, or child) who developed lung cancer increases your own risk by approximately 1.5–2 times, even after adjusting for smoking. This may reflect shared genetic susceptibility, environmental exposures, or both.