Ideal Body Weight Calculator
Devine, Robinson, Miller and Hamwi ideal-weight formulas side by side, plus the healthy BMI range.
"Ideal body weight" formulas were created for drug dosing and insurance tables, not for judging how anyone should look. They are still useful as a rough reference — which is why this tool shows four of them together with the weight range that corresponds to a healthy BMI, so you can see how much they disagree.
The formulas (kg; height over 5 ft in inches)
- Devine: men 50 + 2.3/in; women 45.5 + 2.3/in — the one most clinical dosing tables use.
- Robinson: men 52 + 1.9/in; women 49 + 1.7/in.
- Miller: men 56.2 + 1.41/in; women 53.1 + 1.36/in.
- Hamwi: men 48 + 2.7/in; women 45.5 + 2.2/in.
Example: a 175 cm (68.9 in) man — Devine 70.5 kg, Robinson 68.9 kg, Miller 68.7 kg, Hamwi 72.0 kg; healthy BMI range 56.7–76.3 kg.
Limitations
None of these account for frame size, muscle mass, age or ethnicity, and they were derived mainly from white adult populations. Below about 152 cm (5 ft) they are unreliable. Use the BMI range as the sanity check and treat any single "ideal" number with scepticism.
Sources
- Devine BJ. Gentamicin therapy. Drug Intell Clin Pharm. 1974;8:650-655.
- Robinson JD, et al. Determination of ideal body weight for drug dosage calculations. Am J Hosp Pharm. 1983;40(6):1016-1019.
- Pai MP, Paloucek FP. The origin of the "ideal" body weight equations. Ann Pharmacother. 2000;34(9):1066-1069.
Related: BMI calculator.
Frequently asked questions
Which ideal weight formula is best?
None is "correct" — they differ by several kilograms for the same person. Devine is the most widely used in medicine. For health purposes the healthy BMI range (18.5–24.9) is a better guide, and body composition matters more than either.
Does frame size change ideal weight?
Older tables added or subtracted about 10% for small or large frames. These formulas ignore frame size, which is one reason to read them as a range, not a target.