Why do the formulas disagree?
Devine, Robinson, Miller and Hamwi were each derived from different populations and originally built for drug dosing, not aesthetics. Treat the spread between them as your target range.
Calculate your ideal body weight based on height, gender, and frame size using multiple established medical formulas.
Devine (men) = 50 kg + 2.3 × (inches over 60). Devine (women) = 45.5 kg + 2.3 × (inches over 60). Healthy BMI range = 18.5 to 24.9 × height(m)².
A woman 5 ft 6 in tall has a Devine ideal weight of about 59 kg (130 lb), and a healthy BMI range of 51–68 kg (114–150 lb). Anywhere in that band is clinically normal.
Devine, Robinson, Miller and Hamwi were each derived from different populations and originally built for drug dosing, not aesthetics. Treat the spread between them as your target range.
No. They use height and sex only, so athletes with high lean mass will exceed their 'ideal' weight while being perfectly healthy. Pair the result with a body fat estimate.
Yes — a large frame adds roughly 10% and a small frame subtracts about 10%. Measure your wrist circumference or elbow breadth to judge which end of the range fits you.