How it works
The healthy range comes from the standard BMI range of 18.5 to 24.9: weight = BMI × height², with height in metres. The Devine formula is 50 kg for men (45.5 kg for women) for the first 5 feet of height, plus 2.3 kg for each inch above 5 feet. The two answers differ on purpose — one is a range, the other is a single formula point — and neither is a personal target on its own.
Frequently asked questions
Is the Devine number my ideal weight?
No. It was developed for medicine dosing, not as a personal goal. Treat the range as the more useful guide, and talk to a professional about your own target.
Does muscle change this?
Yes. A muscular person can sit above the range and still be healthy, which is why this is an estimate, not a verdict.