ActiveDay

Ideal Weight Calculator

Four classic formulas — Devine, Hamwi, Robinson, and Miller — plus the healthy BMI range, all from your height and sex.

Enter your height to see ideal weight estimates.

What "ideal weight" actually means

The ideal body weight formulas were never about appearance. Hamwi's formula appeared in 1964 and Devine's in 1974, both built so clinicians could dose medication for a normal-sized body of a given height. Robinson and Miller refined the coefficients in 1983. All four share the same shape: a base weight at five feet, plus a fixed increment per inch of height above it, with separate coefficients for men and women.

Because they were fitted to different populations, the four estimates form a spread — often five kilograms wide or more. That spread is the honest answer: for any height there is a healthy band, not a single correct number.

The formulas

FormulaMenWomen
Devine50 kg + 2.3 kg/inch over 5 ft45.5 kg + 2.3 kg/inch
Hamwi48 kg + 2.7 kg/inch45.5 kg + 2.2 kg/inch
Robinson52 kg + 1.9 kg/inch49 kg + 1.7 kg/inch
Miller56.2 kg + 1.41 kg/inch53.1 kg + 1.36 kg/inch

A better way to use the number

The most useful output of this page is usually not a formula weight but the healthy BMI range shown beneath the results — the weight band where height-adjusted health risk is lowest for most adults. Check where you currently sit with the BMI calculator, and remember that body composition matters more than the scale: a kilogram of muscle and a kilogram of fat weigh the same but mean very different things.

If you decide to move toward the range, the path is the same as any weight goal: a moderate calorie adjustment from the calorie calculator, enough protein, consistent training, and honest tracking. ActiveDay handles the tracking — meals by camera or barcode, workouts from Apple Health, and the weekly trend that tells you whether the plan is working.

Frequently asked questions

  • Why do the formulas give different results?

    Each formula was fitted to different reference data, decades apart, and they diverge more the further your height is from average. Read them as a band of reasonable estimates, not four competing truths.

  • Where do these formulas come from?

    Hamwi (1964) and Devine (1974) were created for clinical drug dosing, not aesthetics. Robinson (1983) and Miller (1983) are later refinements of the same idea. Their persistence owes more to simplicity than precision.

  • Is ideal weight the same as healthiest weight?

    No. Health outcomes track body composition, fitness, and where fat is stored far more closely than scale weight. A muscular person can be healthiest well above their formula weight; the healthy BMI range shown below the table is a broader, more realistic band.

  • What if my ideal weight seems unrealistic?

    Treat it as a distant landmark, not a deadline. Sustainable change is roughly 0.25 to 0.5 kg per week; even partial progress toward the healthy range produces measurable health benefits along the way.

Related tools