Formulas sourced to their original clinical publications
Four numbers, one range
There is no single medically defined "ideal" weight for a given height. This calculator instead shows four independent reference points: the healthy BMI band, and three older formulas built by clinicians named Devine, Hamwi and Robinson. Where the four cluster together is a more useful signal than trusting any one of them alone.
Where each formula came from
| Formula | Origin |
|---|---|
| Devine (1974) | Interdepartmental memo written for U.S. Naval Hospital pharmacy staff, to size drug dosages |
| Hamwi (1964) | Published in a diabetes-education teaching guide for estimating a patient's frame |
| Robinson (1983) | Published in the American Journal of Hospital Pharmacy, refining the Devine method |
None of these three were built with fitness or diet culture in mind. Pharmacists needed a fast way to estimate a patient's lean body size so an IV drip or medication dose scaled to something closer to their actual metabolism than their raw body weight, which can run high due to fat, fluid retention or muscle. Diet and fitness sites picked the formulas up decades later because they were simple, published and free to use, not because they were designed to answer "what should I weigh."
Why we show a range, not a verdict
None of these four numbers accounts for muscle mass, bone density or frame size, and none of them is a target to hit. A number outside the shown range is not automatically a problem, and a number inside it is not automatically healthy on its own. If weight is a genuine health concern for you, a doctor or registered dietitian looking at your full history will give a far better answer than any formula on this page, this one included.
FAQs
Why were these formulas originally created for medicine, not fitness?
Devine, Hamwi and Robinson all built their versions to estimate a patient's lean body size for calculating drug dosages, IV fluid rates and other clinical math where using raw body weight can overdose or underdose someone. Fitness and diet sites adopted them later as general reference points.
Which of the four numbers should I actually use?
None of them individually. The point of showing four is that they cluster into a band rather than a single figure, and that band is more informative than any one formula's output taken alone.
Does this calculator adjust for frame size?
No. None of the four formulas used here take a wrist or elbow measurement, so a naturally large-framed or small-framed person will read the same as anyone else of the same height and sex. That is a real limitation, not an oversight this page is hiding.
Should athletes trust this range?
Treat it as a loose reference rather than a target. Muscle adds weight without adding fat, so a well-trained person commonly sits above every number here. The body fat calculator on this site is a better fit for tracking a muscular build.