PLATE 01 + 02 / HUMAN FACE

Anatomy of proportion

Select a region to explore its structure and evidence.

AnteriorFront

A / FIXED REFERENCE

LateralProfile

B / FIXED REFERENCE

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Selection is linked across both views.

Illustrative anatomy · approximate outlines.
Not a measured “ideal” face.

FORMA FEATURE / MOUTH & LIPS

Mouth width: measurements, ratios, and research

Mouth width is the distance between the corners of the relaxed mouth. It changes substantially with smiling.

How mouth width is measured

Measure corner to corner in a neutral frontal image. Compare with bigonial width (jaw corners) or alar width, but keep the denominator explicit.

Ratios, ranges & competing claims

1 : 2.5 — Mouth width to jaw width

A 101-person eye-tracking and rating study favored mouth width at about 40% of bigonial width among its options, for both male and female faces.

Study: All observers were Caucasian; the result concerns the presented face manipulations. The perception of lip aesthetics in the context of facial proportions

> 1.5 × nose width — A model-sample observation

A study of 50 female models found mouth width greater than 150% of nasal width.

Observation: A female sample’s observation, not a recommended cutoff for men. Do the neoclassical canons still describe the beauty of faces?

Practical takeaway

Compare relaxed mouth width with jaw width.

The study’s mouth-to-jaw proportion offers a more explicit starting point than calling a mouth simply wide or narrow. Use nasal width as a second comparison.

What changes the answer

A wider jaw reduces the ratio even when the mouth stays unchanged. Lip fullness and smiling alter its apparent size, so compare neutral expressions.

Connected facial features

Explore the interactive atlas and compare this feature with both fixed reference views.