Ideal weight calculator
There is no single ideal weight. The four formulas clinicians cite disagree by several kilograms, and they were made for drug dosing rather than as personal targets. They are shown together, next to the healthy BMI range, which has better evidence behind it.
- Healthy BMI range for your height
- 114.6 – 154.3 lb
- Devine (1974)
- 130.7 lb
- Robinson (1983)
- 130.5 lb
- Miller (1983)
- 135.1 lb
- Hamwi (1964)
- 129.4 lb
- Gap between the formulas
- 5.6 lb
Population formulas, not personal medical advice. They take no account of age, build or health conditions; talk to a clinician before setting a weight goal.
The formula
Each formula adds a fixed increment per inch above five feet to a base weight. Devine: men 50 + 2.3/in, women 45.5 + 2.3/in. Robinson: 52 + 1.9 and 49 + 1.7. Miller: 56.2 + 1.41 and 53.1 + 1.36. Hamwi: 48 + 2.7 and 45.5 + 2.2. The BMI range is 18.5 to 24.9 × height².
Worked example
A woman of 168 cm gets 59.6 kg by Devine, 59.4 by Robinson, 61.5 by Miller and 59 by Hamwi, an average of 59.9 kg. The healthy BMI range at that height is 52.2 to 70.3 kg — far wider, and the better guide.
How to use it
- 1Read the BMI range as the answer and the formulas as context. A weight anywhere in that range is consistent with good health.
- 2The formulas ignore frame size and muscle, so a muscular person can sit well above them and be lean.
- 3They are not designed for heights under about 150 cm, where they become unreliable.
Questions people ask
Why do the formulas disagree?
Each was fitted to a different population for a different purpose — dosing medication, setting insurance tables. None was validated as a health target, which is why the gap between them is several kilograms.
Which one should I use?
None of them as a goal. If you want a number to aim for, the healthy BMI range is the evidence-based choice, and a clinician can narrow it for you.
Last reviewed: 2026-10-20