- Craniometry. (of the skull) the ratio of the distance from nasion to the lower margin of the nasal aperture to that of the maximum breadth of the nasal aperture.
- Cephalometry. (of the head) the ratio of the maximum breadth of the external nose to its height from the nasal root to where the septum is confluent with the upper lip.
- the ratio of the widest part of the nose to its length multiplied by 100