IDEAL WEIGHT
CALCULATOR
Calculate your ideal body weight using four clinically validated formulas.
What This Calculator Does
The Ideal Weight Calculator shows your ideal weight across four clinically validated formulas: Hamwi (1964), Devine (1974), Robinson (1983), and Miller (1983). It also shows your healthy BMI weight range — a broader, more realistic target.
The Formula Explained
Devine formula (men): IBW = 50kg + 2.3kg per inch over 5ft. Devine (women): 45.5kg + 2.3kg per inch over 5ft. Example: 5ft 9in (175cm) male → 50 + (9 × 2.3) = 70.7kg ideal weight. The four formulas give a range of 68–76kg for the same person.
What Your Result Means
No single ideal weight exists for a given height — biological diversity is real. The healthy BMI range (18.5–24.9 kg/m²) gives a 15–20kg window that reflects this. More important than hitting a target weight: achieving a healthy body fat percentage (14–24% men, 21–31% women) within a healthy BMI range.
Body Fat Calculator — more meaningful than weight alone · BMI Calculator to check your healthy weight range
What Is Ideal Body Weight?
Ideal body weight (IBW) formulas were originally developed in clinical settings to estimate appropriate drug dosages and assess nutritional status. They produce a single target weight based on height and sex — but should be interpreted as a rough reference range rather than a precise personal target.
The Four Main Formulas
The Hamwi formula (1964): 48kg for men (or 45.4kg for women) plus 2.7kg (or 2.27kg) per inch over 5 feet. The Devine formula (1974), widely used in medicine, uses 50kg for men (or 45.5kg for women) plus 2.3kg per inch over 5 feet. The Robinson formula (1983) and Miller formula (1983) use slightly different baselines. All four formulas have the same fundamental limitation: they do not account for body composition, muscularity, or frame size.
Ideal Weight vs Healthy Weight
The healthy BMI weight range (18.5–24.9) is generally a more useful target than any single ideal weight formula, as it captures the range of weights associated with lowest health risk rather than a single number. The two measures often agree but can diverge for individuals at the tails of the height distribution.