Why There's No Single "Ideal Weight"
Every ideal weight formula was developed for a different purpose — some for medical dosing, others for insurance actuarial tables — and none accounts for muscle mass, bone density, or frame size. This is why a muscular athlete can weigh well above these estimates while being perfectly healthy, and why these numbers are best used as a general reference range rather than a strict target.
Devine Formula
Originally created in 1974 to help calculate medication dosages, the Devine formula has since become one of the most widely cited ideal weight formulas in medicine, despite not being designed for general weight guidance.
Robinson and Miller Formulas
Both are refinements of the Devine formula from the 1980s, adjusting the constants slightly based on updated population data. They tend to produce numbers close to Devine's but not identical.
Hamwi Formula
Developed in 1964 for quick clinical estimates, the Hamwi formula was designed to be calculated by hand without complex math, which is part of why it remains simple compared to more modern approaches.
BMI Range as a Sanity Check
The healthy BMI range (18.5-24.9) offers a broader window than any single formula, converted into a weight range for a given height. Comparing where the formula estimates fall within this range can highlight how much the different methods agree or disagree for a given body type.
What These Numbers Don't Capture
None of these formulas measure body fat percentage, waist circumference, or muscle mass — all of which matter more for health outcomes than weight alone. Two people at the identical "ideal weight" can have very different health profiles depending on body composition, which is why formulas like this are best treated as a starting reference, not a diagnosis.