Ideal Weight Calculator

None is definitively 'correct' — they're all decades-old clinical approximations originally developed for drug dosing, not fitness or aesthetics. The Devine formula (1974) is the most widely used in clinical medicine today, particularly for calculating medication doses. For general reference, averaging all four gives a reasonable midpoint, but individual healthy weight varies with frame size, muscle mass, and body composition far more than these formulas capture.

They were developed independently, at different times, using different population data. Devine (1974) was built for drug dosing calculations. Robinson (1983) and Miller (1983) refined it using different reference datasets. Hamwi (1964) is the oldest and tends to run lower. The spread between them — typically 5-15 lb for a given height — reflects genuine uncertainty in defining a single 'ideal' weight.

Unlike BMI, these formulas calculate a target weight directly from height and sex — your current weight isn't an input, it's what you compare the result against. That's the whole point: they tell you a reference weight to aim for or compare yourself to, rather than evaluating a weight you already have.

Neither alone tells the full story. BMI gives you a range (a healthy span for your height); ideal weight formulas give you a single point estimate. Both ignore muscle mass, bone density, and fat distribution. For most people, the BMI healthy range shown alongside these formulas is the more clinically supported reference — treat the four ideal-weight numbers as historical context rather than a target to hit exactly.

They become less reliable at the extremes. All four formulas add weight linearly per inch above 5 feet, which works reasonably in the typical adult height range but can produce unrealistic numbers for people well outside 5'0"–6'6". They also weren't validated on children, and shouldn't be applied to anyone under 18.

Considerably. None of these four formulas account for skeletal frame size or muscle mass — a broad-framed, muscular person will reasonably weigh more than these formulas suggest while still being lean and healthy. Wrist circumference relative to height is sometimes used clinically to estimate frame size and adjust these targets, but that's beyond what a simple calculator can capture.