⚖️ Ideal Weight Calculator

Compare four classic formulas for estimating ideal body weight — Devine, Robinson, Miller and Hamwi — side by side, from your height and sex.

Units

Metric (cm) Imperial (ft/in)

Sex

Height (cm)

Four formulas, one shape

Every formula here is a base weight at five feet plus a fixed amount for each inch above it. Height is converted to inches first (centimetres divided by 2.54), so only the two constants change:

inches over 5 ft = height in inches - 60      (result in kg)

             men                  women
Devine    50   + 2.3 per in    45.5 + 2.3 per in
Robinson  52   + 1.9 per in    49   + 1.7 per in
Miller    56.2 + 1.41 per in   53.1 + 1.36 per in
Hamwi     48   + 2.7 per in    45.5 + 2.2 per in

At 170 cm - 6.93 in over five feet - a man gets Devine 65.9 kg, Robinson 65.2, Miller 66.0 and Hamwi 66.7, averaging 65.9 kg (145.4 lb). A woman at the same height averages 61.4 kg. The spread between them is part of the answer.

Why they disagree, and where they came from

Hamwi (1964) was written for diabetic diet planning and has the steepest slope, 2.7 kg per inch for men. Miller (1983) is the flattest at 1.41, so the four converge near 5 ft and fan out at the extremes.
Devine (1974) is the one clinicians still use, and it was never about health at all - it was built to scale drug doses to lean body mass.

These take height and sex and nothing else - not frame size, not muscle, not age - and below 5 ft they extrapolate past the range they were fitted on. A healthy weight is a range, not a target.

Frequently asked questions

What is the ideal weight for a 5 foot 7 woman?

The four formulas give 61.4 kg, 60.8 kg, 62.5 kg and 60.7 kg - about 61 kg, or 135 lb. A BMI-based healthy range for that height is wider, roughly 53 to 72 kg.

Which ideal weight formula is most accurate?

None of them, really - they are fitted to different populations for different purposes. Devine is the clinical default; the average of all four is a reasonable single number if you want one.

Why is my ideal weight lower than what I actually weigh?

They describe lean population averages and ignore muscle and build. Plenty of healthy, athletic people sit well above their "ideal" figure and still well inside a healthy BMI range.