Ideal weight calculator
There is no single ideal weight: WHO treats the whole BMI range from 18.5 to 24.9 as healthy. The calculator shows what that range means in kilograms at your height, and below it what the classic formulas give.
At 170 cm, a healthy BMI means anything from 53 to 72 kg — a spread of almost twenty kilograms. Where you belong within it depends on your build, your muscle and where you carry fat, and neither your height nor a formula knows any of that.
The “ideal weight” formulas were not designed as weight-loss targets. The best known, the Devine formula, was published in 1974 for calculating drug doses. The others — Robinson, Miller, Hamwi — were fitted to the same kind of height and weight tables, which is why their results are close (Pai and Paloucek, 2000).
How it works
- Choose your sex and enter your height in centimeters.
- Look at the healthy weight range by BMI: that is the main answer.
- Compare it with the formulas: each gives a point inside the range, and the gap between them is simply how precise the approach is.
How the formulas work
All four American formulas share one design: a base weight for a height of five feet (152.4 cm) plus a fixed amount for every inch (2.54 cm) above it. Devine uses 50 kg plus 2.3 kg per inch for men and 45.5 kg plus 2.3 kg per inch for women. Robinson and Miller refined the coefficients with later data; Hamwi proposed his rule back in 1964.
Below five feet the formulas break down, because the per-inch increment turns negative. The Broca formula — height in centimeters minus 100 — dates from the 19th century and overestimates weight in tall people.
| Height | Healthy weight by BMI |
|---|---|
| 150 cm | 42–56 kg |
| 155 cm | 44–60 kg |
| 160 cm | 47–64 kg |
| 165 cm | 50–68 kg |
| 170 cm | 53–72 kg |
| 175 cm | 57–76 kg |
| 180 cm | 60–81 kg |
| 185 cm | 63–85 kg |
| 190 cm | 67–90 kg |
Frequently asked questions
- Which ideal weight formula is the most accurate?
- None of them measures health: all were derived from mid-20th-century height and weight tables. The healthy BMI range together with your waist measurement is a better guide than a single number from a formula.
- Why do the formulas give different weights?
- Different authors derived them from different data. A difference of a few kilograms between them is the real precision of the approach.
- Does the calculator work for teenagers and older adults?
- Not for teenagers: their weight is assessed with charts for age and sex. In older adults body composition changes with age, and weight is best assessed with a doctor rather than by a formula.
Further reading
More calculators: Body fat calculator, Waist-to-height and waist-to-hip ratio calculator, Water intake calculator, Keto calculator.
This calculator gives an estimate for general information. It is not medical advice, a diagnosis, or a prescription for treatment or a diet, and it does not replace a consultation with your doctor. If you have a health condition, are pregnant, take medication, or follow a diet prescribed to you, decisions about food belong with your doctor.