What Makes a Weight 'Ideal'?
Learn the history, limitations, and key factors used in traditional Ideal Body Weight calculations.
What is IBW?
Ideal Body Weight (IBW) is a guideline derived from historical formulas originally used by physicians for calculating appropriate medication dosages based on patient size. It is not a definitive health measure.
Factors Considered
IBW is primarily determined by Height and Sex. Some calculations also take into account Age and estimated Body Frame size, typically measured via wrist circumference.
Major Limitation
Most IBW formulas ignore Body Composition (muscle vs. fat). This can inaccurately classify highly muscular individuals (like athletes) as "overweight," limiting its usefulness for fitness assessment.
Key Formulas Used
Common formulas include Hamwi, Devine, Robinson, and Miller. These formulas provide slightly different estimates based on a baseline weight for 5 feet, plus a fixed amount per inch over 5 feet.
