Pack-Years for Smoking 20 Cigarettes a Day for 30 Years
Smoking a pack a day for 30 years produces 30 pack-years, a level associated with substantially elevated disease risk.
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How to use this tool
- Enter cigarettes per day and years smoked in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your pack-years and the full breakdown beneath it.
Long-term smokers accumulate pack-years that qualify them for lung cancer screening — calculate your total here.
Frequently asked questions
- What is a pack-year?
- One pack-year equals smoking one pack (20 cigarettes) every day for one year. Smoking half a pack for 20 years also equals 10 pack-years.
- Why do pack-years matter?
- Guidelines recommend annual low-dose CT lung cancer screening for adults aged 50–80 with 20+ pack-years of smoking history. Pack-years are also used to gauge COPD and cardiovascular disease risk.