Lung Age Estimation Calculator

Lung age estimation compares a smoker's actual FEV₁ to what's expected for their age, expressing the result as an equivalent "lung age" — often noticeably older than their real age — as a motivational tool for smoking-cessation counseling.

Estimate Lung Age

cm
Standing height.
Enter a value between 140 and 205.
L
From spirometry.
Enter a value between 0.4 and 6.
yrs
For comparison to lung age.
Enter a value between 18 and 90.
Estimated Lung Age
83
years (lung age)
~38 yrs older than actual
Actual age
45 yrs
Difference
+38 yrs

How It's Calculated

Morris–Temple (height in inches)
Male: 2.87 × ht − 31.25 × FEV₁ − 39.375 · Female: 3.56 × ht − 40.0 × FEV₁ − 77.28

How Old Do the Lungs Act?

Reduced FEV₁ translates into a lung age that can far exceed actual age.

actual age lung age often older

Frequently Asked Questions

Is lung age a validated diagnostic measure?

No — it's a counseling and motivation tool built on real spirometry data, not a diagnostic category on its own. It's used to make reduced lung function tangible during smoking-cessation conversations.

How does lung age help with quitting smoking?

Hearing that your lungs function like those of a much older person can be a powerful, concrete motivator — studies have shown telling smokers their lung age improves quit rates.

How is lung age calculated?

From a regression equation (Morris–Temple) using measured FEV₁ against age-based norms for a person's height and sex.

What if lung age is younger than actual age?

That simply means lung function is better than average for that age — reassuring, and the tool is mainly aimed at highlighting the opposite in smokers.

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