Where these formulas come from#
The Devine, Robinson, Miller, and Hamwi formulas were developed between the 1960s and 1980s, originally for calculating medication doses — not for judging physiques. Each estimates a “reference” weight from height and sex alone, which is why the four numbers disagree with each other by several kilograms. The average is a reasonable middle estimate, and the healthy BMI range (18.5–24.9) gives the wider band that population health data supports.
Why lifters should read this number differently#
None of these formulas know how much muscle you carry. A lifter with years of training can sit well above every estimate on this page — and even above the healthy BMI range — while being leaner and healthier than someone at their “ideal” weight. If you train, body composition is the number that matters: estimate your body fat with the body fat calculator, check your muscularity with the FFMI calculator, and treat scale-weight targets as loose guides rather than goals.
Using it to set a goal weight#
If you are starting a cut or a slow gain and want a sensible target, pick a weight inside the healthy BMI band and adjust for training history — closer to the top of the band if you lift, lower if you are new to training. Then let the calorie deficit calculator or bulking calculator turn that target into a daily calorie number and a realistic timeline.