Why these aren't weight-loss goals
The Ideal Body Weight formulas were developed in clinical contexts where a single target weight is useful as a reference point: calculating drug doses for patients of unusual sizes, setting mechanical ventilator tidal volumes based on lean body mass, or planning surgical anaesthesia. They were never intended as personal health goals.
They have real limitations for anything outside that clinical use:
- No body composition information. A muscular 180 cm man has the same IBW as a sedentary 180 cm man. Body fat percentage and waist measurements matter far more for individual health.
- Sex-binary. All four formulas have separate male and female coefficients with no intermediate option.
- No age adjustment. Mortality-optimal body weight shifts upward with age (see BMI for older adults); IBW does not reflect this.
- No ethnicity adjustment. Derived from largely Western patient populations.
For a personal weight target, use instead
- BMI calculator — produces a weight range (for the “healthy” band) rather than a single point, and the Personalize panel adjusts for ethnicity, age, and waist risk.
- Waist-to-height ratio — the simplest cardiometabolic-risk check; more informative than any IBW formula.
- Body fat % estimator — separates the weight number into fat mass and lean mass, which is what actually matters for health.
The formulas
All four use the same structure: a base weight at 5 ft (60 inches) plus an increment per inch of additional height. Values below are in kilograms; the calculator converts to pounds if you choose imperial units.
- Devine (1974) — Men: 50 kg + 2.3 kg per inch over 5 ft; Women: 45.5 kg + 2.3 kg per inch over 5 ft. The most widely used clinically, especially for drug dosing.
- Robinson (1983) — Men: 52 kg + 1.9 kg per inch over 5 ft; Women: 49 kg + 1.7 kg per inch over 5 ft. Modification of Devine.
- Miller (1983) — Men: 56.2 kg + 1.41 kg per inch over 5 ft; Women: 53.1 kg + 1.36 kg per inch over 5 ft. Produces a tighter spread across heights.
- Hamwi (1964) — Men: 48 kg + 2.7 kg per inch over 5 ft; Women: 45.5 kg + 2.2 kg per inch over 5 ft. The oldest of the four; still referenced in dietetics.
Related reading
Medical disclaimer. This calculator is for general educational use and is not medical advice. Clinical applications of Ideal Body Weight (drug dosing, ventilator settings) should be performed by qualified healthcare professionals using institution-specific protocols.