The four formulas explained
All four formulas take height and biological sex as inputs and use a linear regression based on population studies. They differ in their baseline weights and the increment applied per inch of height above 5 feet (152cm).
| Formula | Year | Male (175cm) | Female (165cm) |
|---|---|---|---|
| Robinson | 1983 | 72.7 kg | 60.0 kg |
| Miller | 1983 | 74.4 kg | 61.7 kg |
| Devine | 1974 | 73.2 kg | 58.6 kg |
| Hamwi | 1964 | 71.7 kg | 58.0 kg |
Why BMI range matters more than a single target
The healthy BMI range of 18.5–24.9 translates to a weight range of roughly 10–15 kg at most heights. This range is more useful than a single formula number because it acknowledges that healthy weight genuinely varies between individuals of the same height.