Harmony & facial ratios
Jaw Slope
1 min read · Updated October 4, 2026
How steeply the lower jawline runs from the jaw corner to the chin.
What it is
Jaw slope is the angle of the lower jawline as it runs from the corner of the jaw (the gonion) to the point of the chin (the menton). It describes whether the jaw runs flat and horizontal or slants steeply toward the chin.
How it's measured
The angle of the jawline against the horizontal is taken on each side and averaged. The app reports 180° minus that angle, so a higher number means a flatter, more horizontal jawline and a lower number a steeper one.
How it's read
A flatter jawline reads as wider and more angular, and a steeper one as more tapered. Ranges are set separately for men and women.
What affects it
Posture, a raised chin and double-chin tissue all change the visible jawline. Keep your head level and chin neutral. Leanness sharpens how defined the jaw looks, which is graded separately under Jaw Definition.
Related measurements
In the same group: Bigonial Width, Jaw Frontal Angle and Deviation of IAA & JFA. 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.