Midface width ratio
Interpupillary distance : face width (Pallett)
How far apart the pupils are as a share of the width of the face. Pallett, Link & Lee (2010) found that raters preferred a value of ≈0.46.
Also searched as interpupillary distance to face width and eye spacing to face width.
How to read it
the pupils are close together relative to face width.
this proportion sits near the value Pallett et al. identified as preferred/average.
the pupils are widely spaced relative to face width.
Reference values by population
| Reference population | Female (mean ± SD) | Male (mean ± SD) | n | Source |
|---|---|---|---|---|
| North American White | 0.46 ± 0.03 | 0.46 ± 0.03 | — | Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov. |
| East Asian | 0.46 ± 0.03 | 0.46 ± 0.03 | — | Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov. |
| South Asian | 0.46 ± 0.03 | 0.46 ± 0.03 | — | Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov. |
| African / African diaspora | 0.46 ± 0.03 | 0.46 ± 0.03 | — | Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov. |
| Middle Eastern | 0.46 ± 0.03 | 0.46 ± 0.03 | — | Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov. |
| Hispanic / Latino | 0.46 ± 0.03 | 0.46 ± 0.03 | — | Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov. |
| Not specified — show pooled | 0.46 ± 0.03 | 0.46 ± 0.03 | — | Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. 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). On a typical photo with 300 px between the pupils, that is about 12 px of wander on every point. Small ratios and angles inherit it, so their intervals are wide. A number without an interval is a number pretending to be more precise than it is.
References
- Pallett, Link & Lee (2010). New "golden" ratios for facial beauty. Vision Res 50(2):149–154. doi.org/10.1016/j.visres.2009.11.003
- Lim, Abdul Shakor & Shaharudin (2022). Reliability and Accuracy of 2D Photogrammetry: A Comparison With Direct Measurement. Front Public Health 9:813058. doi.org/10.3389/fpubh.2021.813058
Common questions
What is midface width ratio?
How far apart the pupils are as a share of the width of the face. Pallett, Link & Lee (2010) found that raters preferred a value of ≈0.46. Same caveats as the vertical ratio.
How is midface width ratio measured from a photo?
It is computed from the face-mesh landmarks (iris_R, iris_L, zy_R, zy_L): dist(iris_R, iris_L) / dist(zy_R, zy_L). Every value carries a 1σ error bar propagated from the landmark detector's published accuracy, with a floor of ± 0.02, so a small difference inside the interval is not a difference.
What is a normal midface width ratio?
Across the reference populations the anatomical norm is the same: 0.46 ± 0.03 for women, 0.46 ± 0.03 for men. This value is provisional and awaits line-by-line audit against the primary tables. Your own value is placed on the distribution you choose, as a percentile with its error bar.
What does a low or high midface width ratio mean?
Below the mean: the pupils are close together relative to face width. Above the mean: the pupils are widely spaced relative to face width.
This is the horizontal optimum from Pallett 2010, measured rather than assumed from a template.
Related measurements
The rest of the eyes set, then the nearest measurements elsewhere on the face. Every one is computed on the same photograph, in the same run, with its own error bar.
Also: how bone-level measurements are taken from a photo · methodology · glossary · all 35 insight pages