Ideal Body Weight Calculator

What this tool does

The Ideal Body Weight Calculator works out a reference body weight from just your height and sex, using the four formulas most commonly cited in clinical and fitness settings side by side: Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964). Each was developed independently — mostly for calculating medication dosing — so they don't agree exactly, which is exactly why seeing all four (plus their average) gives a more honest picture than trusting any single number.

It also compares that result against the weight range a "normal" BMI (18.5–24.9) would cover at the same height, which is typically much wider — a useful reminder that these formulas are reference points, not a single correct target weight for every body.

How to use the ideal weight calculator

• Select your sex — every formula here uses different constants for men and women.
• Enter your height in feet/inches or centimeters.
• Read off all four formula results in kg and lb, plus their average.
• Check the BMI-range comparison for context on how wide a "normal" weight range actually is at your height.

Common use cases

• Medication dosing reference — the Devine formula in particular was designed for, and is still used in, calculating certain drug dosages based on body weight.
• Fitness goal-setting context — a reference point to weigh against (no pun intended) alongside body composition, strength goals, and how you actually feel.
• Comparing formulas — students and clinicians who need to see how Devine, Robinson, Miller, and Hamwi diverge for the same height.
• General curiosity — a quick, no-signup way to see where these commonly-cited numbers land for your height.

Frequently asked questions

Which ideal body weight formula is "correct"?

None of them is more objectively correct than the others — they're different statistical approximations built from different population data decades apart. Devine is the most widely used in clinical dosing today, but Robinson and Miller are considered by some researchers to fit modern population data slightly better.

Is ideal body weight the same as a healthy weight?

Not exactly. These formulas were built for medical dosing calculations, not as personal weight targets — they don't account for muscle mass, frame size, or body composition, so a muscular person can weigh well above their "ideal" weight and be perfectly healthy.

Why do the four formulas give different results for the same height?

Each was derived from a different reference population and uses a different per-inch adjustment above 5 feet — Hamwi tends to run leaner for taller people, while Miller tends to give a higher baseline, which is exactly why comparing all four side by side is more useful than picking just one.

Do these formulas work for very short or very tall heights?

They were validated mainly on average adult height ranges — results can feel less reliable at the extremes (very short or very tall), which is part of why the BMI-range comparison is shown alongside them for extra context.

Should athletes use these formulas?

Generally no — because none of these formulas account for muscle mass, an athlete or bodybuilder will typically weigh more than their "ideal" weight while carrying a healthy or even low body fat percentage; body composition metrics are more useful for that population.