Facial thirds, fifths, canthal tilt and the golden ratio all started as drawing conventions - ways for artists to place features on a page consistently. They are genuinely useful vocabulary and much weaker evidence than the internet suggests. This guide explains both halves.
Vertically, a face is conventionally divided into three roughly equal bands: hairline to brow, brow to base of nose, base of nose to chin. Horizontally, into five eye-widths across. Real faces vary from this constantly, and the variation is most of what makes a face recognisable. The measurement is a description, not a target.
The claim that 1.618 governs facial beauty is far older than the evidence for it and much repeated. Studies that look for it find weak and inconsistent effects, and the masks built around it mostly measure how closely a face resembles an averaged composite. It is a fine piece of design history and a poor personal standard.
No face is symmetrical. Jaws sit slightly off-centre, eyes sit at slightly different heights, and one side of almost everyone's smile is stronger. Mirroring one half of a photo produces a face that looks uncanny rather than better, which tells you most of what you need to know about symmetry as a goal.
Does this rate my face?
No. It explains what each measurement means and how it is taken. It does not score anyone, and it will say so if asked.
Is a face with perfect thirds more attractive?
The research does not support that cleanly. Memorable faces very often break the convention, and the convention exists to help artists be consistent rather than to define beauty.
What is canthal tilt?
The angle between the inner and outer corners of the eye. It varies enormously between individuals and between ethnic groups and is a neutral descriptive measurement, nothing more.
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