How ideal weight is calculated
Ideal body weight formulas were first created to help doctors dose medicines, not to set personal goals. Each starts with a base weight for someone 5 feet (152 cm) tall and adds a fixed amount for every inch above that. They give a single number, which is why it helps to compare several and look at the healthy BMI range too.
| Formula | Men | Women |
|---|---|---|
| Devine (1974) | 50 kg + 2.3 kg per inch over 5 ft | 45.5 kg + 2.3 kg per inch |
| Robinson (1983) | 52 kg + 1.9 kg per inch | 49 kg + 1.7 kg per inch |
| Miller (1983) | 56.2 kg + 1.41 kg per inch | 53.1 kg + 1.36 kg per inch |
| Hamwi (1964) | 48 kg + 2.7 kg per inch | 45.5 kg + 2.2 kg per inch |
Why a range beats a single number
Frame size, muscle, age and where you carry weight all change what is healthy for you. Two people of the same height can both be healthy at weights 10 kg apart. The healthy BMI range of 18.5 to 24.9 captures that spread, which is why most doctors use it rather than one exact target.
Next steps
Once you have a target, see how long it will take with the weight loss calculator, find your daily needs with the calorie calculator, and check your body composition with the body fat calculator, which says more about health than weight alone.
Sources: Devine BJ, Drug Intell Clin Pharm 1974; Robinson JD et al., Am J Hosp Pharm 1983; Miller DR et al., Am J Hosp Pharm 1983; Hamwi GJ, 1964; WHO BMI classification.
