Glossary
What is midface ratio?
Last updated: May 22, 2026
Midface ratio is the proportion of the middle third of the face (from the brow line to the nose base) compared to the other thirds (upper third: hairline to brow line; lower third: nose base to chin). The classical proportion holds the three thirds approximately equal. A midface that is proportionally long or short relative to the other thirds materially affects how a face reads.
How midface ratio is measured
Measured by dividing the vertical face into three sections at the brow line and nose base. The midface portion is then expressed as a fraction of total face height or as a ratio against the upper and lower thirds. IPD calibration anchors the absolute measurements to a known scale.
Why midface ratio matters
Midface proportion is a primary driver of how 'balanced' a face reads. Disproportionate midface length (either too long or too short) can make even otherwise excellent features read less harmoniously. Midface volume loss with age also affects this ratio visually.
Normal range
Classical ideal: midface third equals approximately 33% of total face height, with all three thirds roughly equal. Wider tolerance: 30 to 37%. Outside this range, the midface starts visually dominating or under-supporting the rest of the face.
Source: Standard cephalometric references
How Facet uses midface ratio
Facet measures the midface ratio from the front-facing photo's landmark detection and compares it against gender and ethnicity-keyed ideals.
Frequently asked
Can midface ratio be changed?+
Structural midface proportion is fixed once skeletal growth completes. Visual midface proportion can be modified by cheek filler (volume restoration), brow lift, or rhinoplasty (which subtly shifts the perceived midface boundary). Skin quality and contouring also affect the visual read.
Why does midface ratio matter for cosmetic procedures?+
Skilled aesthetic surgeons consider midface proportion when planning procedures. Cheek filler placed too high or too low can shift the perceived midface ratio in unflattering directions. Rhinoplasty changes the nose base position, which subtly redefines the midface boundary.