Pack-Years for 40 Cigarettes a Day for 25 Years

Smoking 40 cigarettes a day for 25 years equals 50 pack-years.

Embed this tool on your site

<iframe src="https://abracalc.com/calculator/pack-years-calculator/40-cigs-25-years/embed.html" width="340" height="320" style="border:1px solid #e4e7ec;border-radius:12px" loading="lazy"></iframe>

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.

Calculate the high pack-year burden of smoking two packs daily for 25 years.

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.