How ideal weight is estimated
Each formula sets a base weight at 5 feet (60 inches) of height and adds a fixed amount for every inch above that. The widely used Devine formula:
Men: 50 kg + 2.3 kg × (inches over 60)
Women: 45.5 kg + 2.3 kg × (inches over 60)
For a 70-inch (5′10″) man that's 50 + 2.3 × 10 = 73 kg, about 161 lb. Robinson, Miller, and Hamwi use the same idea with different constants, which is why the four results form a range.
Treat it as a range, not a target
These formulas use only height and gender, so they can't see your build or muscle. An athlete may weigh more than the "ideal" yet be lean and healthy. Pair the result with your BMI and, if you want body composition, the body fat calculator.
Frequently asked questions
How is ideal body weight calculated?
The common formulas all start from a base weight at 5 feet of height and add a set amount per inch above that. The Devine formula, for example, uses 50 kg + 2.3 kg per inch over 5 feet for men, and 45.5 kg + 2.3 kg per inch for women.
Which ideal weight formula is best?
There is no single best one — they were developed for different purposes, mostly medication dosing. Devine is the most widely cited, Robinson and Miller tend to read a little lower, and Hamwi is a quick clinical estimate. Looking at the range across all four is more useful than any single number.
Is ideal body weight the same as a healthy weight?
Not exactly. These formulas depend only on height and gender, so they ignore build, muscle, and body composition. A muscular person may sit above their "ideal" figure yet be perfectly healthy. Use it as a rough reference alongside BMI and body-fat measures.
Do these formulas work for very short or very tall people?
They are least reliable at the extremes, since they assume a linear increase per inch from a 5-foot base. For heights well under 5 feet some formulas can give unrealistically low numbers, so treat the results as a guide rather than a strict target.
How can I find a healthy weight range instead of one number?
A BMI-based range is a good complement: a BMI of 18.5 to 24.9 is considered healthy, which spans a band of weights for your height. Combine that range with these ideal-weight estimates for a fuller picture.
Disclaimer: Ideal-weight formulas were designed largely for clinical dosing and are rough guides only. This is not medical advice — talk to a healthcare professional about a weight that's right for you.