Ideal body weight (IBW) is a calculated "desired" weight for a given height and sex. An important nuance: these formulas were originally invented not for aesthetics but to calculate drug doses in patients with obesity, where real weight cannot be relied on.
So ideal body weight should be seen as a rough guide, not a goal. It does not distinguish muscle from fat, so it is useful to complement it with BMI, body fat percentage and an assessment of body composition.
Reference ranges
There is no single "ideal" figure — there are several formulas that give close results (height in cm):
| Devine (1974), men | 50 + 0.9 × (height − 152) |
| Devine (1974), women | 45.5 + 0.9 × (height − 152) |
| Hamwi (1964), men | 48 + 1.1 × (height − 152) |
| Hamwi (1964), women | 45.4 + 0.9 × (height − 152) |
| Broca (historical) | approximately height(cm) − 100 |
What an elevated level means
A real weight noticeably above the ideal is a reason to assess not so much the fact itself as the waist and the fat fraction: in an athlete the "excess" may be muscle, while in abdominal obesity it may be dangerous fat.
What a low level means
A real weight noticeably below the ideal may reflect either a good constitution or a weight deficit with loss of lean body mass — especially risky for older people.
How the test is done
Choose a formula (Devine is used most often), plug in the height in centimeters and get the weight in kilograms. For example, a man 178 cm tall by Devine: 50 + 0.9 × (178 − 152) = 50 + 23.4 ≈ 73 kg. Different formulas will give results within a few kilograms of each other.
What affects the value
- Body build (asthenic/hypersthenic) is not taken into account by the formulas.
- Muscle mass: in athletes the ideal weight is understated.
- Choice of formula changes the result by a few kilograms.
Calculate using this marker
Calculators where Ideal body weight is used directly:
Frequently asked questions
Which ideal-weight formula is best?
The Devine formula is used most often, but Hamwi, Robinson and Miller give close figures. All of them are rough guides and do not account for the proportion of muscle and fat, so there is no single "correct" number.
Is ideal body weight a weight-loss target?
No. It is a medical calculation (originally for drug dosing), not a personal goal. For health, a normal body fat percentage and preserved muscle mass matter more than matching a formula.