Harmony & facial ratios
Lower Third Proportion
1 min read · Updated October 4, 2026
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.
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.
Related measurements
In the same group: Top Third, Middle Third and Lower Third. The full list is on the Harmony overview.
See it on a full report
Open the sample report to see every measurement, score and highlight on a real example.