Health Ideal weight calculator
See what the four classic ideal-weight formulas say for your height, how far apart they are, and the BMI range that is more useful than any of them.
Healthy weight range for this height
56.7 kg to 76.3 kg
From the WHO healthy BMI band of 18.5 to 24.9. This is the range worth using.
What the four classic formulas say
- Formula average
- 70.0 kg
- Spread
- 3.3 kg
- Healthy BMI band
- 56.7 kg-76.3 kg
The four formulas disagree by 3.3 kg at this height. They were derived in the 1960s to 1980s for calculating drug doses, not for telling anyone what to weigh, which is why the BMI range above is the more useful answer.
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Cite this page
Reembun. (2026, July 28). Ideal weight calculator. https://reembun.com/ideal-weight-calculator
How to use it
Set units, sex and height
Those three are all the classic formulas need.
Read the spread, not one number
Devine, Robinson, Miller and Hamwi are shown together, and they disagree by several kilograms. The honest answer is the band they cover.
Compare it with the BMI band
The healthy BMI range for your height sits alongside, and it is wider than any single formula suggests.
Treat it as a starting point
These formulas were built for drug dosing, not for body goals. Frame, muscle and age move the real answer.
The four formulas
All four share the same structure: a base weight at 5 feet (152.4 cm), plus a fixed increment for every inch above that.
| Formula | Men | Women |
|---|---|---|
| Devine (1974) | 50 kg + 2.3 kg/inch | 45.5 kg + 2.3 kg/inch |
| Robinson (1983) | 52 kg + 1.9 kg/inch | 49 kg + 1.7 kg/inch |
| Miller (1983) | 56.2 kg + 1.41 kg/inch | 53.1 kg + 1.36 kg/inch |
| Hamwi (1964) | 48 kg + 2.7 kg/inch | 45.5 kg + 2.2 kg/inch |
A worked example
A man 180 cm tall is 10.87 inches above five feet:
| Formula | Result |
|---|---|
| Devine | 75.0 kg |
| Robinson | 72.7 kg |
| Miller | 71.5 kg |
| Hamwi | 77.4 kg |
A spread of 5.9 kg between the highest and lowest, for the same person. That spread is the most honest thing this page can show you: there is no single ideal weight to calculate.
What the formulas were actually for
Devine’s equation was published in a 1974 pharmacy journal as a way to estimate a dosing weight for gentamicin. It was never validated as a health target, and Devine himself offered no derivation. The others followed the same pattern, refitting the constants to different data.
They persist in clinical practice for exactly the purpose they were built for, namely drug dosing, ventilator tidal volumes and renal function estimates, where a reproducible number matters more than a physiologically meaningful one.
The range that is more useful
The WHO healthy BMI band of 18.5 to 24.9 gives a range rather than a point:
| Height | Healthy weight range |
|---|---|
| 160 cm | 47.4 to 63.7 kg |
| 165 cm | 50.4 to 67.8 kg |
| 170 cm | 53.5 to 72.0 kg |
| 175 cm | 56.7 to 76.3 kg |
| 180 cm | 59.9 to 80.7 kg |
| 185 cm | 63.3 to 85.2 kg |
At 175 cm that is a 20 kg span. Two people at opposite ends of it are both within the healthy band, and the difference between them is mostly muscle, frame and where they carry weight, none of which a height-based formula can see.
Better measurements
Waist-to-height ratio. Keep your waist under half your height. One measurement, no table.
Waist circumference. Risk rises above 94 cm for men and 80 cm for women, with lower thresholds recommended for South and East Asian populations.
Body fat percentage. More informative than weight for anyone who trains, and measurable with a tape measure.
If a formula tells you that you should weigh 8 kg less than you do, check it against a waist measurement before acting on it. The formula does not know whether the difference is fat or muscle, and that distinction is the entire point.
Common questions
Which ideal weight formula is correct?
None of them, exactly. Devine, Robinson, Miller and Hamwi were all derived between 1964 and 1983, mostly to calculate drug doses from height, and they disagree by several kilograms at the same height. The healthy BMI range is a better answer because it is a range, which is what a healthy weight actually is.
Why do the formulas disagree so much?
They were fitted to different populations for different purposes, and they all share the same crude shape: a base weight at five feet plus a fixed increment per inch. That linear increment is the weak point, since body mass does not scale linearly with height.
Do these formulas account for build or muscle?
No. They take height and sex and nothing else. A muscular person and a sedentary person of identical height get identical answers, which is exactly the limitation that makes body fat percentage or waist-to-height ratio more informative.
What should I use instead?
Waist-to-height ratio is the single most useful number here: keep your waist under half your height. It needs one measurement, no chart, and predicts cardiometabolic risk better than weight-for-height in most studies.
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