Harmony & facial ratios
Facial thirds: the four measurements
6 min read · Updated November 1, 2026
Four measurements describe how the height of your face is divided: the three thirds from hairline to chin, and the split inside the lower third between the lip and the chin.
How these fit together
The three thirds share one total, the distance from hairline to chin, so they always add up to 100%: a taller forehead has to take its height from somewhere. The fourth measurement looks inside the lower third. Read the four as one set, because a miss in one shows up in the others. For the history and the research behind the rule, see the Facial thirds guide.
A worked example
Take a face where, in pixels measured down the image, the hairline sits at 120, the brow line at 330, the base of the nose at 540 and the bottom of the chin at 780. Hairline to chin is 660. The basic arithmetic is below; the app applies small calibration adjustments on top of it.
| Band | Height (px) | Share of 660 px |
|---|---|---|
| Top third | 210 | 31.8% |
| Middle third | 210 | 31.8% |
| Lower third | 240 | 36.4% |
Illustrative numbers, not a real person.
Top Third
The forehead band, from the hairline to the brow line, as a share of total face height.
What it is
The face divides into three horizontal bands. The top third is the forehead: it runs from the hairline down to the brow line. It is expressed as a percentage of the full height from hairline to chin, so a perfectly even face would read about 33% in each band.
How it's measured
The brow line, the hairline and the bottom of the chin are placed from detected landmarks, in a frame levelled by your eye line so a tilted head doesn't skew the result. The hairline is the hard part: hair, a fringe or a receding line move the visible edge, so it is estimated from the face's own landmarks instead of read off the pixels. That makes the top third the least precise of the three thirds.
Definition: hairline to brow line, divided by hairline to chin, × 100. The brow line sits midway between each brow's head and inner corner, averaged over both brows.
How it's read
Most analyses treat a figure near a third, give or take a few points, as balanced. A somewhat taller or shorter forehead is very common on attractive faces, so a small miss here carries little weight. Ranges are set separately for men and women, but the difference between them is small.
What affects it
Hairstyle changes how tall your forehead looks without changing the measured number much, because the hairline is estimated. The biggest source of error is camera angle: pitching your head up or down changes how tall each band looks, and not in a way you can correct by eye. If the number surprises you, retake the photo level and straight on first.
For more detail, see the full guide: Facial thirds.
Middle Third
The band from the brow line to the base of the nose, as a share of total face height.
What it is
The middle third holds your eyes and nose. It runs from the brow line down to the base of the nose (the subnasale) and is shown as a percentage of the full hairline-to-chin height.
How it's measured
Both ends come from landmarks: the brow line is taken midway along each brow, and the nose base is the point where the nose meets the upper lip. The result is expressed against the same total height as the other two thirds, so the three always add up to 100%.
Definition: brow line to the base of the nose, divided by hairline to chin, × 100.
How it's read
A middle third close to the other two reads as a balanced, compact face. A long middle third gives a longer nose or midface; a short one can make features look crowded together. Because the three thirds share one total, a miss in one shows up in the others too.
What affects it
This band is stable against hair and styling, so it is usually the most trustworthy of the three. Head pitch still moves it, because tilting your head up or down changes how much of the nose region the camera sees. For a clean reading, keep the camera at eye level and your head level.
For more detail, see the full guide: Facial thirds.
Lower Third
The band from the base of the nose to the bottom of the chin, as a share of total face height.
What it is
The lower third contains the mouth, jaw and chin. It runs from the base of the nose to the lowest point of the chin (the menton) and is shown as a share of the full face height.
How it's measured
The nose base and chin bottom are landmark points, measured vertically in a levelled frame and divided by the hairline-to-chin height. Like the other thirds, the number is a share of one shared total.
Definition: base of the nose to the bottom of the chin, divided by hairline to chin, × 100.
How it's read
A lower third a little longer than the others is common in adult faces and often reads as mature and strong, particularly on men. A very long lower third can look elongated, and a very short one can look compressed. Ideal ranges differ slightly between men and women.
What affects it
Smiling, opening your mouth or lifting your chin all change this band, so keep a relaxed closed mouth. Leaner cheeks and a defined jaw change how the lower face looks more than they change the measurement.
For more detail, see the full guide: Facial thirds.
Lower Third Proportion
How the lower third is split between the upper lip area and the lip-to-chin area.
What it is
This looks inside the lower third. The distance from the base of the nose to the line where the lips meet (the stomion) is compared with the full distance from the nose base to the chin. The classic reference is that the upper lip area takes about a third of the lower face and the lip-to-chin area about two thirds, a 1:2 split.
How it's measured
The line between the lips is placed midway between the inner edges of the upper and lower lip, in a levelled frame. The number reported is the upper portion as a percentage of the whole lower third.
Definition: base of the nose to the midpoint of the lip seam, divided by base of the nose to the bottom of the chin, × 100.
How it's read
Values near a third are read as a balanced lower face. A higher figure means a longer upper lip area relative to the chin; a lower one means a shorter upper lip or a longer chin. Mouth position is easy to disturb, so expression matters here.
What affects it
Any smile, pout or open mouth changes where the lips meet. Use a relaxed, closed, neutral mouth. A lip line that sits oddly because of the photo is the most common cause of an unexpected value.
See it on a full report
Open the sample report to see every measurement, score and highlight on a real example.