Free Ideal Body Weight Calculator (Devine, Robinson, Miller, Hamwi)
See your ideal body weight from four classic formulas and the healthy weight range for your height.
Your details
Results
About this calculator
"Ideal body weight" formulas were created in the 1960s–80s to estimate healthy weights and, later, to calculate drug doses. They estimate weight from height and sex only, so they cannot account for muscle mass, frame or age.
Because the four formulas disagree by a few kilograms, this tool shows all of them plus the healthy-weight range derived from BMI.
How it works
Each formula starts with a base weight for 5 feet (60 inches) of height and adds a fixed amount per extra inch:
| Formula | Men | Women |
|---|---|---|
| Devine (1974) | 50 + 2.3 kg/in | 45.5 + 2.3 kg/in |
| Robinson (1983) | 52 + 1.9 kg/in | 49 + 1.7 kg/in |
| Miller (1983) | 56.2 + 1.41 kg/in | 53.1 + 1.36 kg/in |
| Hamwi (1964) | 48 + 2.7 kg/in | 45.4 + 2.27 kg/in |
How to read your result
Treat the range as more useful than any single number. Health outcomes depend more on body composition, waist size, fitness and metabolic markers than on matching a formula. If you are muscular, you may weigh more than these formulas without any health concern.
Worked example
A woman who is 165 cm tall.
| Average of four formulas | 57.7 kg 127.2 lb |
| Devine | 56.9 kg 125.5 lb |
| Robinson | 57.4 kg 126.6 lb |
| Miller | 59.8 kg 131.9 lb |
| Hamwi | 56.7 kg 124.9 lb |
| Healthy BMI range (18.5–24.9) | 50.4–67.8 kg 111–149 lb |
Frequently asked questions
What is a healthy weight for my height?
A BMI of 18.5–24.9 is the standard healthy range for most adults, shown here as a weight range. For people of South Asian origin lower cut-offs for risk may apply (see our BMI calculator).
Which ideal weight formula is most accurate?
None is. They are rules of thumb. The Devine formula is the most widely used in clinical dosing.
Is ideal body weight used for drug dosing?
Yes. Several drugs are dosed on ideal or adjusted body weight in people with obesity. Always follow the product label and local protocols.
Limitations and when not to use
Not valid for children, pregnancy, or athletes with high muscle mass. Does not diagnose underweight or overweight.
Sources and references
- Devine BJ. Gentamicin therapy. Drug Intell Clin Pharm 1974;8:650–655.
- Robinson JD, et al. Determination of ideal body weight for drug dosage calculations. Am J Hosp Pharm 1983;40:1016–1019.
- Miller DR, et al. Am J Hosp Pharm 1983;40:1622–1625.
- Hamwi GJ. Therapy: changing dietary concepts. In: Diabetes Mellitus: Diagnosis and Treatment, ADA, 1964.
Last updated: 2026-10-09