Head · Medical · Core
Head Girth
The circumference of the head.
HeadGirth
How to measure
Application
Used as the primary circumference measurement for hat, helmet, and headwear sizing across all industries.
Posture
Head level, looking straight ahead.
Landmark
Tape sits just above the ears and across the mid-forehead, at the point of maximum circumference.
Tool
Tape measure.
Common mistake
Placing the tape too high on the forehead or too low at the back reduces the measurement below the true maximum circumference.
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": "HeadGirth",
"gender": "Female",
"age": 34,
"percentile": 50,
"country": "US",
"unit": "cm"
}{
"measurement": "HeadGirth",
"gender": "Female",
"country": "US",
"value": 54.7,
"unit": "cm"
}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.