Body Frame Size Calculator
Quick answer
Find out whether you have a small, medium or large body frame from just two measurements: your height and your wrist circumference. This calculator uses the classic height-to-wrist ratio (Grant’s index) with sex-specific cut-offs and shows exactly where you fall on a visual scale.
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The height-to-wrist ratio (Grant’s index)
r = height (cm) ÷ wrist circumference (cm)
Men: r > 10.4 small · 9.6–10.4 medium · r < 9.6 large
Women: r > 11.0 small · 10.1–11.0 medium · r < 10.1 large
How to measure your wrist: wrap a flexible tape snugly — but not tight — around the narrowest part of your wrist, just above the wrist bone, where you would wear a watch. Both measurements must use the same unit so the ratio stays valid.
Worked example
- 1
A woman is 168 cm tall and measures her wrist at 15.5 cm.
- 2
r = 168 ÷ 15.5 ≈ 10.84.
- 3
The women’s medium band is 10.1–11.0, so 10.84 falls in the middle — medium frame.
- 4
With a 15.0 cm wrist instead: r ≈ 11.2 → small frame. Near a boundary, measurement technique matters.
Frame size by height-to-wrist ratio
| Your result | Category | What it means |
|---|---|---|
| Men r > 10.4 · Women r > 11.0 | Small frame | Slender bones relative to your height. It says nothing about strength or health — it describes skeletal build only. |
| Men 9.6–10.4 · Women 10.1–11.0 | Medium frame | A typical, mid-range build relative to height — the most common classification. |
| Men r < 9.6 · Women r < 10.1 | Large frame | Broader bones for your height. This does not imply excess weight — frame size is structure, not fat. |
| Near a threshold | Re-measure | If your ratio sits close to a boundary, tape placement changes the answer. Take two readings on the same wrist and average them. |
Wrist circumference works as a skeleton proxy because the wrist carries almost no fat or muscle. Measure at the narrowest point, just above the wrist bone.
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This calculator provides general estimates for informational purposes only and is not medical advice. For personal guidance, consult a qualified healthcare provider.