🚬 Pack-Years Calculator (Smoking)
Quantify cumulative cigarette exposure in pack-years for risk and screening.
Clinical takeaway
USPSTF: age 50–80, ≥ 20 pack-years, current or quit < 15 yr → annual low-dose CT.
Loading calculator…
Paste the link in Slack, Teams, X, or LinkedIn — the preview image comes from this page’s Open Graph card.
When to use
Lung cancer screening eligibility and tobacco risk assessment.
How it works
Pack-years = (cigarettes per day ÷ 20) × years smoked.
Key points
- USPSTF: age 50–80, ≥ 20 pack-years, current or quit < 15 yr → annual low-dose CT.
- 1 pack-year = 20 cigarettes/day for 1 year.
- Document quit date for screening windows.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Cigarettes per day | 20 /day |
|---|---|
| Years smoked | 30 years |
→Pack-years30.0pack-years
- Formula：(cigarettes/day ÷ 20) × years
- Lung cancer screening：USPSTF: age 50–80 with ≥ 20 pack-years (current or quit < 15 yr) — consider annual low-dose CT.
Frequently asked questions
- What is Pack-Years Calculator (Smoking)?
- Quantify cumulative cigarette exposure in pack-years for risk and screening.
- How is Pack-Years Calculator (Smoking) calculated? What is the core formula?
- Pack-years = (cigarettes per day ÷ 20) × years smoked.
- When is Pack-Years Calculator (Smoking) used?
- Lung cancer screening eligibility and tobacco risk assessment.
- What are the key clinical points for Pack-Years Calculator (Smoking)?
- USPSTF: age 50–80, ≥ 20 pack-years, current or quit < 15 yr → annual low-dose CT. 1 pack-year = 20 cigarettes/day for 1 year. Document quit date for screening windows.
- What are the limits and cautions when using Pack-Years Calculator (Smoking)?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- How is Pack-Years Calculator (Smoking) calculated in practice? Can you show a worked example?
- Inputs: Cigarettes per day 20 /day, Years smoked 30 years → Result: Pack-years 30.0 pack-years（Formula: (cigarettes/day ÷ 20) × years, Lung cancer screening: USPSTF: age 50–80 with ≥ 20 pack-years (current or quit < 15 yr) — consider annual low-dose CT.）