Head · Medical · Specialist
Back Of Head To Tragion
The distance from the back of the head to the tragion point.
BackOfHeadToTragion
How to measure
Application
Used in headset, hearing protection, and eyewear temple design to determine the internal depth of the head at ear level.
Posture
Head level, looking straight ahead.
Landmark
The tragion is the small notch at the top of the ear canal opening where the ear meets the face. Measured from this point to the most rearward point of the skull at the same height.
Tool
Tape measure or spreading caliper.
Assistance
A second person should locate the tragion and the rearmost skull point and hold the tape ends in place.
Common mistake
Measuring from the outer edge of the ear rather than the tragion notch inflates the result.
API example
Request a predicted value for a 34-year-old woman at the 50th percentile in the United States. Adjust age, percentile, gender, and country to match your design scenario.
POST https://api.humanform.app/v1/predict
Authorization: Bearer hf_live_...
Content-Type: application/json
{
"measurement": "BackOfHeadToTragion",
"gender": "Female",
"age": 34,
"percentile": 50,
"country": "US",
"unit": "cm"
}Response values depend on age, percentile, gender, and country. Create a free dashboard account to run live predictions.
See design examples for worked scenarios that combine multiple measurements, or read the methodology page for percentile-based design thinking.
Explore the dataset
Humanform covers 148 measurements with country-adjusted predictions and separate female and male profiles. Browse the full inventory or read the API reference for request syntax.