Ideal Weight Calculator
The Devine number and the healthier answer: the range for your height.
How this is calculated
Devine: 50 kg (M) / 45.5 kg (F) + 2.3 kg per inch over 5 ft · Range: 18.5–24.9 × height(m)²
Worked example: male, 180 cm → 10.87 inches over five feet, so 50 + 2.3 × 10.87 = 75.0 kg (165 lb). The healthy-BMI band for that height runs 59.9–80.7 kg — a 20-kg-wide corridor, which is exactly why the single number should be read as a landmark, not a destination. Not medical advice.
Frequently asked questions
What is the "ideal weight" formula?
This page shows the Devine formula (1974) — 50 kg (men) or 45.5 kg (women) plus 2.3 kg per inch over five feet — alongside the healthy-BMI range for your height (18.5–24.9 × height²). Devine gives one number; the BMI band gives an honest range.
Why does the range matter more than the single number?
Because "ideal" varies with build and muscle. The Devine number was originally derived for drug dosing, not aesthetics or health targets; the WHO healthy-BMI band is wide on purpose. If the single number and your reality disagree, the band is the saner reference.
Is ideal weight different for men and women?
In the Devine formula, yes — the starting constant differs (50 vs 45.5 kg) reflecting average body composition. The healthy-BMI band is the same for adults of any sex, which is one of its known simplifications.
Should I aim for this number?
Treat it as a reference line, not a finish line. Muscular people sit above it healthily; the healthy-BMI band, waist measurement, and how you feel and perform carry more signal. For personal targets, a professional beats any formula. Not medical advice.