Work out frame size from wrist instantly with clear inputs, formula shown and shareable results.
Frame size is estimated from the ratio of height to wrist circumference, because wrist girth is almost entirely bone and skin rather than fat or muscle. For men a ratio above 10.4 indicates a small frame and below 9.6 a large one. Ideal body weight tables are conventionally adjusted about 10% down for small frames and up for large ones.
Frame ratio
ratio = height(cm) / wrist circumference(cm)
Men's bands
above 10.4 small, 9.6 to 10.4 medium, below 9.6 large
These figures are population-average estimates, not a medical assessment or diagnosis. Body composition equations carry errors of several percentage points, and healthy ranges vary with age, ethnicity, muscularity and medical history. Discuss weight or body composition goals with a qualified clinician or dietitian.
Both work, but the wrist has almost no soft tissue, so the measurement is unaffected by body fat.
It shifts the middle of the range modestly. It does not move the boundaries of the healthy BMI band, which are set by outcome data.