Facial thirds balance
How evenly your face divides into three vertical thirds — forehead, midface, and lower face.
Why it matters
Roughly equal thirds is a long-standing balance cue; a very short or long third skews how mature or juvenile the face reads.
What the facial thirds measure
Facial thirds divide the front of the face into three horizontal compartments stacked from top to bottom. The upper third runs from the hairline down to the brow line, the middle third from the brow to the base of the nose, and the lower third from the nose base to the bottom of the chin. The idea traces back to the proportional canons artists used to lay out a head, later formalised in anthropometry by Farkas.
This tool reports how evenly the three match one another. A value of 1.0 would mean the three segments are exactly equal in height, and the number climbs as one segment grows longer or shorter than the others. Real faces almost never land at a flat 1.0 - they sit somewhat above it - so the score is best read as 'how close to balanced', not as pass or fail.
Why the balance registers
Vertical balance is one of the first things the visual system samples when it takes in a face. When one third is markedly longer or shorter than its neighbours, the face can read as older or younger, or heavier in the brow or the jaw, before any single feature stands out. The upper third tends to vary the most between people, because the hairline shifts with age, genetics and styling.
It helps to treat equal thirds as a long-standing compositional convention rather than a law of attractiveness. It describes a kind of evenness that many faces happen to share; it does not rank a face's worth, and plenty of widely admired faces carry an obviously dominant third.
How the hairline is found
The top boundary - the trichion, or midline hairline - is the one point the face mesh cannot place, because the mesh stops at the forehead. Rather than ask you to mark it, we detect it automatically from the face-skin silhouette: the segmentation that separates skin from hair traces your real hairline, including receding or widow's-peak shapes, and we read the top of that silhouette at the midline.
That makes the upper third an honest measurement rather than an estimate. The other two boundaries - the glabella at brow level and the nose base - come straight from the mesh, so all three segments are grounded in your photo.
The conventional range and its limits
The balance band used here is roughly 1.0 to 1.20, where 1.0 represents perfectly equal thirds and more even generally reads as more balanced.
The honest caveat is that the equal-thirds canon is fragile. Farkas et al. 1985, revisiting the neoclassical canons in young adults, found that the canons - equal thirds among them - rarely held exactly in the faces they measured, and that they vary with ancestry and sex. Read your value loosely rather than as a verdict.
What is adjustable and what is bone
The most honest levers here are cosmetic and photographic. Hairstyle does real work on the upper third: a fringe, added height on top, or a different hairline shape changes how long that segment looks. Brow grooming nudges the boundary between the upper and middle thirds, and camera height matters - shooting from above or below foreshortens one third and stretches another, so a neutral, eye-level photo gives the truest read.
The vertical heights themselves are set by the skeleton - the height of the forehead, the maxilla and the mandible - and those are fixed in adults. Procedures such as genioplasty or orthognathic surgery can change segment heights, but they are major interventions mentioned here only for completeness, not as a suggestion.
Typical range
~1.00-1.20 (even thirds — more even is better)
Forehead, midface and lower face should be roughly equal in height (trichion→glabella, glabella→subnasale, subnasale→menton). Value is the spread of the three (1.0 = equal). The hairline (trichion) is auto-detected from the face silhouette.
What your reading means
- Typical
- Your facial thirds are well balanced.
- Less common
- Your thirds are close to even, with one slightly longer or shorter.
- Distinctive
- One of your thirds is notably longer or shorter than the others.
How we measured it
We auto-detect your hairline from the face silhouette, then measure hairline→brow, brow→nose-base, and nose-base→chin, and report how even the three are (1.0 = equal).
The evidence
A neoclassical canon (Farkas 1985): real faces rarely match exactly and vary by ancestry and sex, so read loosely. The upper third uses the auto-detected hairline.
References
- Farkas, L. G., Hreczko, T. A., Kolar, J. C., & Munro, I. R. (1985). Vertical and horizontal proportions of the face in young adult North American Caucasians: revision of neoclassical canons. Plastic and Reconstructive Surgery, 75(3), 328-337.
- Naini, F. B. (2011). Facial Aesthetics: Concepts and Clinical Diagnosis. Oxford: Wiley-Blackwell.