Ideal Body Weight: Complete Guide
Ideal body weight (IBW) formulas estimate the weight range associated with optimal health for a given height. Originally developed by physicians for drug dosing calculations, they've become widely used as health benchmarks - though they have important limitations.
The Four Major IBW Formulas
| Formula | Men (Base + per inch over 5 ft) | Women | Origin |
|---|---|---|---|
| Hamwi (1964) | 48 kg + 2.7 kg/in | 45.5 kg + 2.2 kg/in | Clinical pharmacokinetics |
| Devine (1974) | 50 kg + 2.3 kg/in | 45.5 kg + 2.3 kg/in | Medication dosing |
| Robinson (1983) | 52 kg + 1.9 kg/in | 49 kg + 1.7 kg/in | Actuarial tables |
| Miller (1983) | 56.2 kg + 1.41 kg/in | 53.1 kg + 1.36 kg/in | Life insurance data |
Limitations of Ideal Weight Formulas
- No muscle/fat distinction: A 180 lb athlete with 10% body fat has the same "weight" as a 180 lb sedentary person with 35% body fat.
- Frame size ignored: People with larger bone structures naturally weigh more without excess fat.
- Population bias: Most formulas were developed in specific demographics and may not apply universally.
- Better alternative: Use body fat percentage + BMI + waist circumference together for a more complete picture.
Sources & References
- Hamwi GJ. Therapy: changing dietary concepts. In: Danowski TS, ed. Diabetes Mellitus: Diagnosis and Treatment. Vol 1. New York: American Diabetes Association; 1964:73-78.
- Devine BJ. Gentamicin therapy. Drug Intell Clin Pharm. 1974;8(11):650-655.
- Robinson JD, et al. Estimation of ideal body weight in adults. DICP Ann Pharmacother. 1983;17(7–8):601-606.
- World Health Organization. Obesity: preventing and managing the global epidemic. WHO Technical Report Series 894. Geneva: WHO; 2000.