About the ideal weight calculation
Ideal body weight formulas were built for clinical drug dosing, not for aesthetics, and they all descend from the same 1960s insurance tables. They are useful as a rough anchor — but the BMI healthy range is a better target, because a single "ideal" number ignores frame size and body composition entirely.
Formula
All four share one shape: a base weight at 5 ft, plus a per-inch increment.
Devine men 50.0 + 2.30/in women 45.5 + 2.30/in
Robinson men 52.0 + 1.90/in women 49.0 + 1.70/in
Miller men 56.2 + 1.41/in women 53.1 + 1.36/in
Hamwi men 48.0 + 2.70/in women 45.5 + 2.20/inWorked example
A man 175 cm tall is 8.9 inches over 5 ft. Devine: 50 + (2.3 × 8.9) = 70.5 kg.
Frequently asked questions
Why do the four formulas disagree?
They were derived from different populations at different times, and none was intended as a health target. The spread between them — often 5 kg or more — is an honest reflection of how imprecise the concept is.
Should I actually aim for this weight?
Not literally. The healthy BMI range for your height is a better target, and body composition matters more than either. Someone 5 kg above their "ideal" weight with good muscle mass is healthier than someone at it with none.
Do these account for frame size?
No. That is their main weakness. A broad-framed person can sit well above these numbers at a perfectly healthy body composition. Wrist circumference is sometimes used to adjust, but it is a crude correction.
Sources
- Devine BJ — Gentamicin therapy (1974)
- Robinson JD, et al. — Determination of ideal body weight (1983)