About the Ideal Weight Calculator
"Ideal weight" formulas were originally developed for clinical use, particularly for calculating medication dosages where body weight matters, not as personal fitness targets. Because different researchers derived their formulas from different population samples and decades, no single formula is universally "correct" — which is why this tool shows all four side by side.
The G.J. Hamwi (1964), B.J. Devine (1974), J.D. Robinson (1983), and D.R. Miller (1983) formulas all estimate ideal body weight from height alone, using a base weight at 5 feet and an incremental adjustment per inch above that. Averaging the four tends to smooth out the quirks of any single formula.
Frequently Asked Questions
Should I try to weigh exactly what this calculator says?
No. These are population averages meant as a general reference point, not a personal target. Frame size, muscle mass, and body composition all affect what's healthy for a specific individual.
Why do the four formulas give different results?
Each was derived from different research populations and decades, using different statistical methods — the spread between them illustrates just how approximate any single "ideal weight" number really is.
Are these formulas still used by doctors today?
The Devine formula in particular is still commonly used in clinical settings for calculating medication dosages, though it's rarely presented to patients as a personal weight goal.