Ideal Weight Calculator (Devine, Robinson, Miller, Hamwi)
Get four reference ideal-weight values from the Devine, Robinson, Miller, and Hamwi formulas, plus the BMI 18.5-24.9 healthy range — all from your height and sex.
How it works
Why four formulas?
The 'ideal weight' concept doesn't have one official answer. Different clinical formulas give different numbers because they were derived from different populations and for different purposes (drug dosing, life-insurance tables, etc.). At 5'10' / 178 cm a man could be 'ideal' anywhere from 73 kg (Hamwi) to 78 kg (Miller) depending on which you trust.
Showing multiple references and the WHO BMI healthy range (18.5-24.9 BMI) lets you see the realistic spread. Most adults sit comfortably anywhere across this band; there's no single number you have to hit.
What each formula was designed for
Devine (1974) was originally for calculating drug dosages in tall adults — it's still the default in many hospital pharmacies. Robinson (1983) and Miller (1983) refined Devine using updated population data. Hamwi (1964) was created for diabetes care and uses the same '5 feet base' structure.
All four formulas grow linearly with height above 5 feet (152 cm), with women weighted lower than men. None handle people much shorter than 5 feet well — they extrapolate badly. The WHO BMI range is a better guide for very short or very tall people.
How to interpret your numbers
If your weight falls inside the WHO range, you're statistically 'normal' for your height. If it falls inside or near the four formula values, you're at the body weight clinical references would consider unremarkable. If you're a muscular athlete, all of these will probably underestimate your healthy weight; the formulas don't account for body composition.
These numbers are not goals. They're not personal targets. They're statistical references designed for population-level decisions like drug dosing. For personal weight goals, work with a clinician who can account for your body composition, history, and medical context.
Frequently asked questions
›Which formula is correct?
None is uniquely 'correct'. They were designed for different populations and purposes. Use the spread and the BMI range together to see the realistic ideal-weight band for your height.
›Why is the result different for men and women?
Average body composition differs between sexes; the formulas reflect this. For people on hormone therapy or otherwise outside the binary, neither set is perfect — talk to a clinician.
›What if I'm under 5 feet (152 cm)?
All four formulas were calibrated for adult heights and produce unreliable extrapolations under 5 feet. Use the BMI range instead.
›Does this account for muscle mass?
No. All four formulas use only height and sex. Muscular athletes typically weigh 10-20% more than 'ideal weight' formulas suggest while still being healthy.
›Is this a target weight?
No. Treat it as a clinical reference, not a personal goal. Real weight goals depend on your starting point, health, and lifestyle.
›Why do hospitals use Devine for drug dosing?
Many drug doses are calculated by 'ideal body weight' to avoid overdosing tall or obese patients. Devine has been the historical default for these calculations for decades.
›How does this differ from BMI?
BMI gives you a category from your weight and height. Ideal-weight formulas reverse the question: 'what should the weight be for this height?'
›Does input data leave my browser?
No — everything is computed locally.
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