There is no single “ideal” weight
The four formulas on this page disagree with each other, and that disagreement is the most useful thing about them. For a 175 cm man they return figures spanning roughly 69 to 72 kg — a three-kilogram spread from the same height and sex.
The reason is that none of them were derived from research into optimal health. Devine (1974) was built for calculating drug dosages. Hamwi (1964) came from diabetes practice. Robinson and Miller (both 1983) were attempts to fit population data more closely. They survive because they are quick, not because any one is authoritative.
Read them as a band rather than a target. If the four formulas cluster around 70 kg and the healthy BMI range for your height spans 57 to 76 kg, the honest conclusion is that anywhere in that region is defensible — and that body composition and how you feel matter more than closing the gap to a specific decimal.
Reading the four formulas
Choose metric or imperial units, select your sex, and enter your height. The calculator shows the ideal body weight from four established formulas — Robinson, Miller, Devine, and Hamwi — alongside the healthy weight range for your height based on BMI. Everything is worked out in your browser.
Why show four formulas?
“Ideal weight” is not a single scientific constant. Several formulas exist, each built from different populations and originally intended for different uses, so they disagree by a few kilograms. Rather than pick one and present it as the truth, this tool lays them out together so you can see the sensible range they collectively point to.
Reading the result sensibly
Treat these numbers as a reference band, not a target to chase to the decimal. Because the formulas rely only on height and sex, they cannot see muscle, frame size, or body composition — the same limitation as BMI. If your weight sits within the healthy BMI range shown here and you feel well, you are almost certainly fine. For personal goals, body composition and fitness are better guides than any single ideal-weight figure, and a healthcare professional can give advice tailored to you.