Compare the four 'ideal weight' formulas
Devine, Robinson, Miller, Hamwi — they disagree by kilograms because each was fit to a different insurance table. Seeing all four keeps any single one honest.
Tools used in this guide
The job
'Ideal body weight' formulas all anchor at 5 ft and add a fixed number of kg per extra inch — they differ only in the constant and the per-inch slope. Medical dosing (aminoglycosides, ventilator settings) still uses them.
Height in, four numbers out
Enter height and sex. The tool shows all four formulas plus the BMI 18.5–24.9 range — the spread between them is the honest answer to 'what should I weigh'.
Worked example
At 180 cm (5 ft 11 in), a man sees roughly Devine 75 kg, Robinson 73, Miller 72, Hamwi 72 — a ~3.5 kg spread. The BMI 18.5–24.9 range brackets all of them at ~60–81 kg. None of it knows your frame.
Where it stops
1940s–80s insurance data, mostly white American adults; no frame size, muscle mass, or age. Heights 140–230 cm only — the formulas are not valid outside their fitting range, and 5 ft itself floors them all.