Philtrum : chin
The length of your philtrum (nose base to upper lip) relative to the lip-to-chin distance.
Why it matters
A long upper lip ages the lower face; a shorter philtrum with visible upper-tooth show reads youthful.
What the philtrum ratio measures
The philtrum is the vertical channel of skin between the base of the nose and the top edge of the upper lip, the small grooved area running down to the lip border. This metric compares the height of that segment, from the nose base to the upper lip, against the distance from the upper lip down to the chin.
Reported as a ratio, it places the upper-lip region in proportion to the rest of the lower face. On this scale the measured value sits around 0.30, with the balanced band running from about 0.24 to 0.36. Naini 2011 is the clinical reference behind this proportion.
Why upper-lip length reads the way it does
The existing guidance puts it plainly: a long upper lip tends to age the lower face, while a shorter philtrum, often paired with a little upper-tooth show at rest, tends to read as more youthful. This is because the visible length of skin between nose and lip lengthens with age, and tooth show at rest decreases. The metric captures where your upper lip sits along that spectrum relative to the chin.
As ever, this is a descriptive convention about how faces tend to be perceived, with real variation by individual, ancestry and sex. It is not a measure of anything beyond proportion.
The range, caveats, and reading your own value
A value inside roughly 0.24 to 0.36 means the philtrum length is in a commonly balanced range; below it the upper lip reads short, above it relatively long. The number depends on consistent landmarks, so a neutral mouth and a level head matter, and lip posture (pressed versus relaxed) can shift the upper-lip boundary.
Because this ratio uses the lip-to-chin distance as its reference, it can move for reasons that have nothing to do with the philtrum itself. A short or long chin segment changes the denominator, so the same upper-lip length can land at a different ratio on two different faces. That is one more reason to read it directionally rather than chasing a decimal: whether the upper lip is long or short for your lower face is the useful takeaway, and it should always be read alongside the lower-third balance, since the two describe overlapping regions.
What is fixed and what is changeable
Philtrum length is largely fixed anatomy and lengthens gradually with age; it is not something grooming or exercise changes. Presentation still affects the reading: a relaxed mouth, level head and eye-height camera give the truest figure, and the way you hold your lips changes apparent tooth show.
The one structural option documented in Naini 2011 is a surgical lip lift, which shortens a long philtrum and increases upper-tooth show. That is a permanent cosmetic procedure with its own risks and recovery, included here purely as factual information rather than a suggestion. For most readers, the honest summary is that this metric describes a largely fixed feature.
Typical range
~0.24-0.36
Length of the philtrum (nose base to upper lip) relative to the lip-to-chin distance.
What your reading means
- Typical
- Your philtrum length is well balanced.
- Less common
- Your philtrum is close to the preferred proportion.
- Distinctive
- Your upper lip reads relatively long or short.
How we measured it
We compare the nose-base to upper-lip segment against the upper-lip to chin segment.
The evidence
philtrumRatio.caveat