🎯 Ideal Weight Calculator

Where "ideal weight" formulas come from

The best-known formulas — Devine, Robinson, Miller, Hamwi — all take the same shape: a base weight at five feet, plus a fixed amount per additional inch, with different constants for men and women.

Their origin is worth knowing. The Devine formula was published in 1974 to calculate drug dosages, not to define a healthy body. It was never derived from health outcome data, and the others are similar refinements of the same clinical shortcut. They persist because they are simple, not because they are validated.

Because the formulas differ, they produce a range rather than a single number — and that range is the honest answer. For a 5'10" man the various formulas span roughly 10 kilograms.

A range beats a target

A healthy weight is better expressed as a band than a point. The BMI healthy range of 18.5 to 24.9 translates to a spread of 15 to 20 kilograms for most adult heights, and people are healthy throughout it.

Body composition matters more than the number on the scale. Two people at identical weight can differ substantially in muscle mass, and the one with more muscle will generally have better metabolic markers. A body fat estimate and a waist measurement add information the scale cannot.

What actually predicts health

Waist circumference and waist-to-height ratio track cardiometabolic risk more closely than weight alone, because they capture where fat is stored. A widely used rule of thumb is keeping your waist under half your height.

Cardiorespiratory fitness is another strong independent predictor — fit individuals at higher weights frequently show better outcomes than unfit individuals at lower weights. Blood pressure, resting heart rate, and blood glucose tell you more about health than any weight formula.

If you are setting a goal, a modest and sustained change usually delivers more benefit than reaching a specific number. Losing five to ten percent of body weight is associated with meaningful improvements in blood pressure and blood sugar, regardless of whether any "ideal" figure is reached.

Common questions

Why do the formulas disagree?

Because they were developed independently for different purposes with different constants. None is authoritative; treat the spread as the useful information.

Do they account for frame size?

Not directly. Some clinicians adjust by around ten percent for small or large frames, estimated from wrist circumference or elbow breadth.

Are these appropriate for athletes?

Generally not. Formulas based on height alone systematically misclassify people with high muscle mass.