Measurement reference · FaceFluent editorial · September 13, 2026
Upper lip share of lower third
Of the distance from the base of the nose to the chin, the share taken up above the mouth opening. The convention puts it at about a third.
Also called upper lip share of the lower third, facial thirds.
Reference range
None.
Historical drawing canons provide context for this proportion. We do not display a numerical target band or treat those canons as population norms.
How we calculate it
The vertical gap from the base of the nose down to the mouth line, divided by the whole distance from the base of the nose to the chin.
What moves the number
Jaw position and lip posture. An open or tense mouth shifts the mouth line and therefore the ratio.
What it cannot tell you
Farkas found the vertical canons to be the least often met of all the ones he tested. The historical one-third convention is a habit of illustration, not a validated target for our scanner.
References
Some familiar facial proportions come from artistic conventions. Their history does not make them universal targets.
Read: Facial thirds and drawing conventionsThe scanner calculates this on your own device. Nothing is uploaded.
Run the free scannerThis page is educational. It is not a clinical assessment, a diagnosis, or a claim about how you look. Read the methods and limitations.