How the healthy weight calculator works
Why a range and not a number
BMI categories are bands, and your height maps them to a weight interval roughly 25–45 lb wide. Within it, differences of 10–15 lb matter far less than habits and markers. Picking a single "goal weight" from the middle of the range is a motivational tool at best; the range itself is the health claim.
Boundaries, in plain language
The 18.5 line marks where underweight risks begin (bone density, immunity, hormonal function). 25 marks where population-level cardiometabolic risk starts climbing. 30 marks the obese threshold, where risks compound. Between 18.5 and 25 is the zone where the population data is quietest — and where individual variation (frame, muscle, ethnicity) has the most room.
Frame size and the honest edge cases
Wrist measurement and shoulder width hint at frame, and clinicians adjust informally: broad-framed individuals sit comfortably at the upper edge, narrow-framed at the lower. The range absorbs most of this — another reason targets should live inside it, not at its lines.