What does “ideal weight” mean?
Ideal body weight formulas estimate a typical healthy weight for a given height and sex. They were developed decades ago, mainly so doctors could calculate medication doses, and they are still used in hospitals today. They are useful as a reference point, not as a personal target.
The four ideal weight formulas
Each formula starts from a base weight at 5 feet (152.4 cm) tall and adds a fixed amount for every inch above that.
| Formula | Men | Women |
|---|---|---|
| Robinson (1983) | 52 kg + 1.9 kg per inch over 5 ft | 49 kg + 1.7 kg per inch over 5 ft |
| Miller (1983) | 56.2 kg + 1.41 kg per inch over 5 ft | 53.1 kg + 1.36 kg per inch over 5 ft |
| Devine (1974) | 50 kg + 2.3 kg per inch over 5 ft | 45.5 kg + 2.3 kg per inch over 5 ft |
| Hamwi (1964) | 48 kg + 2.7 kg per inch over 5 ft | 45.5 kg + 2.2 kg per inch over 5 ft |
The calculator shows the result of each, the lowest-to-highest range and the average.
Ideal weight vs a healthy BMI range
The healthy BMI range (18.5 to 24.9) gives a much wider window for your height than the formulas. For a 180 cm (5 ft 11 in) person, it runs from about 60 to 81 kg (132 to 178 lb). Both are shown in the result, because together they give a clearer picture than either alone.
Why muscle changes the answer
Muscle is denser than fat and weighs more for the same volume. People who strength train often weigh more than their formula result while having low body fat and excellent health. If that is you, judge progress by body fat, waist size, strength and how you feel, rather than the scale.
Research behind this calculator
- Pai MP, Paloucek FP (2000). The origin of the “ideal” body weight equations. Annals of Pharmacotherapy.
- Rothman KJ (2008). BMI-related errors in the measurement of obesity. International Journal of Obesity.
Last updated September 21, 2026.