Why the formulas disagree
These equations were created decades ago, mostly to dose medicines, not to set personal goals. They only use height and sex — not age, frame size or muscle. That is why it is better to treat them as a rough guide and look at the healthy BMI range, which is wider and accepted by health agencies.
The formulas
| Formula | Men (kg) | Women (kg) |
|---|---|---|
| Devine | 50 + 2.3 per inch over 5 ft | 45.5 + 2.3 per inch |
| Robinson | 52 + 1.9 per inch | 49 + 1.7 per inch |
| Miller | 56.2 + 1.41 per inch | 53.1 + 1.36 per inch |
| Hamwi | 48 + 2.7 per inch | 45.5 + 2.2 per inch |
Check where you are now with the BMI calculator and body fat calculator.
Sources & review
Checked against these sources on November 10, 2026. Rules and rates can change — always confirm with the official source.
Ideal Weight Calculator FAQs
Which formula is most accurate?
None is “right” for everyone. Many clinicians still use Devine for medicine dosing. For personal health, the BMI range plus waist size is more useful.
Do these work for people under 5 feet?
They were designed for adults 5 ft and taller; results for shorter adults are less reliable.
Is my information stored?
No.