Body Frame Size Calculator
Enter your height and wrist circumference to estimate whether you have a small, medium, or large body frame — a reference sometimes used alongside weight charts, since 'ideal' weight ranges shift depending on frame size.
How the Body Frame Size formula works
The height-to-wrist ratio method:
Ratio = Height (in) / Wrist circumference (in)
Men: ratio above 10.4 is small frame, 9.6–10.4 is medium, below 9.6 is large. Women: ratio above 11.0 is small frame, 10.1–11.0 is medium, below 10.1 is large.
Step-by-step calculation
- Measure your wrist circumference at its narrowest point, just below the wrist bone.
- Divide your height by your wrist circumference (same units) to get the ratio.
- Compare the ratio against the sex-specific thresholds to determine frame size.
Worked example
A woman who is 65 inches tall with a 6-inch wrist: Ratio = 65/6 ≈ 10.83, which falls in the medium frame range (10.1–11.0).
Frequently asked questions
Why does frame size matter for weight charts?
Older height-weight tables (like some insurance charts) provided different 'ideal' weight ranges for small, medium, and large frames, on the idea that bone structure affects a healthy weight independent of fat. Modern guidance leans more on BMI and other measures, but frame size still shows up in some references.
How precise is the wrist-ratio method?
It's a simple approximation, not a precise measurement of bone structure — different methods (like elbow breadth) exist and can give somewhat different classifications.