Which ideal weight formula is most accurate?

None is a measure of health. Robinson is the most commonly cited, and Devine remains standard for clinical drug dosing, but they were built for different purposes.

Does frame size change ideal weight?

The Hamwi method traditionally adds or subtracts 10% for large or small frames. The other formulas do not adjust for frame at all.

Is a healthy BMI range better than an ideal weight number?

A range is usually more useful, because it acknowledges that many weights can be healthy at a given height.

Do these formulas apply to athletes?

Poorly. Athletes carrying above-average muscle will exceed every formula here while being lean.

Ideal Weight Calculator

Compare the Robinson, Miller, Devine and Hamwi ideal-weight formulas plus the healthy BMI range.

Enter your details and your result will appear here.

What Is Ideal Weight?

This calculator shows what four widely cited ideal body weight formulas return for your height and sex, and compares them with the weight range that corresponds to a healthy BMI. Seeing the spread is the point: the formulas disagree, and none of them is authoritative.

Understanding Your Ideal Weight Result

Ideal body weight formulas came out of clinical medicine, not fitness. Devine originally published his in 1974 to standardise drug dosing, and the others followed with revised constants fitted to different data. They all take the same shape: a base weight at 5 feet tall plus a fixed increment per additional inch. Because they use only height and sex, they cannot account for frame size, muscle mass or age.

How Is Ideal Weight Calculated?

Robinson (male): 52 kg + 1.9 kg per inch over 5 feet

Methodology

Robinson (1983), Miller (1983), Devine (1974) and Hamwi (1964) are each computed from your height and sex, and the results are converted back to your chosen units. The healthy BMI range is calculated separately as the weight corresponding to a BMI of 18.5 and of 24.9 at your height.

Worked Example

For a man who is 6 ft 0 in, the Robinson formula gives 52 kg + 1.9 x 12 inches over 5 ft = 74.8 kg (165 lb). Devine returns 77.6 kg (171 lb), Miller 73.1 kg (161 lb) and Hamwi 80.7 kg (178 lb), while a healthy BMI spans roughly 137 to 184 lb.

Important Limitations

These formulas ignore body composition entirely, so a muscular person can be well above their "ideal" weight while being lean and healthy. They were derived from mid-20th-century populations and are not calibrated for all ethnic groups, and they say nothing about health outcomes. Treat a healthy weight as a range you feel and function well within, not a single target number.

Frequently Asked Questions

Which ideal weight formula is most accurate?: None is a measure of health. Robinson is the most commonly cited, and Devine remains standard for clinical drug dosing, but they were built for different purposes.
Does frame size change ideal weight?: The Hamwi method traditionally adds or subtracts 10% for large or small frames. The other formulas do not adjust for frame at all.
Is a healthy BMI range better than an ideal weight number?: A range is usually more useful, because it acknowledges that many weights can be healthy at a given height.
Do these formulas apply to athletes?: Poorly. Athletes carrying above-average muscle will exceed every formula here while being lean.