Nose-to-Mouth RatioHow AI measures this feature and photo tips
The nose-to-mouth ratio compares nasal width to mouth width and the vertical distance between nose base and upper lip. Balanced ratios contribute to lower-third harmony in facial proportion scoring.
See this feature in action with our Face Analyser, Face Shape Analyzer, or Guess My Age.
Key Characteristics
- ✦Nose width vs mouth width at rest
- ✦Philtrum length
- ✦Nasolabial fold prominence
- ✦Smile widening effect on mouth
- ✦Lower third vertical balance
Analysis & Photo Tips
- 📸Closed-mouth front photo for baseline
- 📸Smile analysis uses different landmarks
- 📸Avoid shadow under nose that widens appearance
- 📸Profile view shows nose-lip projection
Related Features
Nose
The nose anchors midface proportion — its width, length, and projection balance the eyes and mouth. Nasal geometry interacts with facial thirds and contributes to profile harmony in AI analysis.
Lips
Lips are key expressive features affecting smile scoring, perceived warmth, and lower-face proportion. Fullness, symmetry, and smile dynamics all feed into Smile Tracker's blendshape and landmark analysis.
Facial Thirds
Classical proportion divides the face into three equal vertical zones: upper (hairline to brows), middle (brows to nose base), and lower (nose base to chin). Deviations signal unique character and affect harmony scores.
FAQ — Nose-to-Mouth Ratio
What is a balanced nose-to-mouth ratio?
Classical guides suggest mouth width roughly equals the distance between the inner iris edges, with nose width near the inner eye corners.
Why does this ratio matter in AI scoring?
Facial proportion algorithms weight midface and lower-face ratios when computing harmony and symmetry scores.
Can the ratio change with expression?
Yes. Smiling widens the mouth significantly while nose width stays constant, temporarily shifting the ratio.