Philtrum length : chin height
Length of the philtrum (subnasale to upper vermilion border) as a fraction of soft-tissue chin height (sublabial fold to menton).
How to read it
the philtrum is short relative to the chin — the configuration associated with a youthful lower face, since the philtrum lengthens with age.
philtrum length relative to chin height sits close to the reference mean.
the philtrum is long relative to the chin. Philtrum length increases through adult life; this ratio is one of the more age-sensitive proportions in the lower face.
Both endpoints are soft-tissue landmarks and the chin height is pitch-sensitive (a chin-down photo shortens it). Read with the pitch value in the capture-quality panel.
Reference values by population
| Reference population | Female (mean ± SD) | Male (mean ± SD) | n | Source |
|---|---|---|---|---|
| North American White | 0.381 ± 0.063 | 0.388 ± 0.06 | 2326 | Farkas 1994/2005 (NA White young adults) prov. |
| East Asian | 0.382 ± 0.066 | 0.382 ± 0.063 | 618 | Farkas 2005 (Chinese/Japanese/Vietnamese/Thai pooled); Jayaratne 2012 (Southern Chinese, n=103) prov. |
| South Asian | 0.371 ± 0.064 | 0.382 ± 0.063 | 210 | Farkas 2005 (Indian); Metgudmath 2022 prov. |
| African / African diaspora | 0.386 ± 0.068 | 0.372 ± 0.063 | 300 | Farkas 2005 (African-American, Zulu, Angolan) prov. |
| Middle Eastern | 0.389 ± 0.063 | 0.388 ± 0.06 | 348 | Farkas 2005 (Turkish, Iranian, Egyptian); Al-Sebaei 2015 (Saudi, n=168) prov. |
| Hispanic / Latino | 0.377 ± 0.064 | 0.377 ± 0.062 | 120 | Farkas 2005 (Mexican-American) prov. |
| Not specified — show pooled | 0.381 ± 0.066 | 0.381 ± 0.064 | 3922 | Unweighted pool of the six groups above prov. |
Where these numbers come from
Transcribed from the cited anthropometric literature; SDs of ratios are propagated conservatively (independence assumed). Entries marked prov. await line-by-line audit against the primary tables — see the norm provenance note.
Why every value has an error bar
Every value Canthion reports carries a 1σ uncertainty propagated from MediaPipe Face Mesh's published accuracy (3.96% of inter-ocular distance mean absolute error per landmark, Kartynnik 2019). For a typical 300 px inter-pupil photo that is ≈12 px per landmark, which is why small ratios and angles get wide intervals. A number without an interval is a number pretending to be more precise than it is.
References
- Farkas, Katic & Forrest (2005). International Anthropometric Study of Facial Morphology in Various Ethnic Groups/Races. J Craniofac Surg 16(4):615–646. doi.org/10.1097/01.SCS.0000171847.58031.9E
Related: how bone-level measurements are taken from a photo · methodology · all insights