Ideal Weight Calculator
See your estimated ideal body weight across four classic formulas, plus the healthy weight range your height supports by BMI.
The classic formulas
Each estimates a reference weight from a base plus an increment per inch over 5 feet:
Robinson (men): 52 kg + 1.9 kg × (inches over 60)
Women use lower base weights; a healthy BMI range gives a band instead of a point.
A man at 5'9" (175 cm): the four formulas land around 150–170 lb, and the healthy BMI range is roughly 128–169 lb.
Take these as reference points, not targets
These formulas were built decades ago for medication dosing, not as health goals — so treat the spread of numbers as a ballpark, not a verdict. A healthy BMI range or, better, a healthy body fat percentage is more meaningful, especially for muscular builds that will read "over" on every height-only formula. If you're aiming to change weight, set a calorie plan with the calorie calculator.
Frequently asked questions
What is my ideal body weight?
No single number — formulas cluster around a range (150–170 lb for a 5'9" man). A healthy BMI band is more useful.
Which formula is best?
None is authoritative; they were built for drug dosing. Use a BMI range or body fat instead.
Does ideal weight account for muscle?
No — height and sex only, so athletes read high. Body fat % is better for them.
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Medical disclaimer: Ideal-weight formulas are rough reference estimates, not health targets or medical advice. Your healthy weight depends on body composition and overall health — consult a healthcare provider. Last reviewed: July 2026.