Ideal Weight Calculator and Healthy Range

What it is

An ideal weight is a reference weight for your height. It comes up at check-ups and in diet advice, but the number changes by several kilograms depending on the formula. Enter your height and sex and this calculator puts the normal weight range, based on a BMI of 18.5 to 22.9, at the top. Below it sit the BMI-based standard weight, the modified Broca rule and the Devine formula, each with its source. If you add your current weight, it also tells you how far you are from the range. Everything is calculated in your browser.

How to use

1. Pick your sex and enter your height in centimeters.
2. Current weight in kilograms is optional. If you add it, you see the gap to the normal range.
3. Read the normal weight range at the top first.
4. Compare the formula results and their lowest to highest values.
5. Check the math lines to see how your numbers were used.

The male 170 cm and 70 kg in the boxes are an example, so replace them with your own.

How it works

• Normal range: a BMI of 18.5 to 22.9 from the Korean Society for the Study of Obesity guideline 2022, multiplied by height in meters squared. This is stricter than the WHO upper limit of 24.9.
• BMI standard weight: height (m)² × 22 for men or 21 for women, plus a both-sexes line using 22. This comes from Samsung Medical Center health information, a secondary source.
• Modified Broca: (height cm − 100) × 0.9. It is widely quoted in Korean hospital handouts, but it is a secondary source and the original could not be verified.
• Devine: 50 kg for men or 45.5 kg for women, plus 2.3 kg for each inch over 60. Devine BJ, Drug Intell Clin Pharm 1974;8:650-655, with coefficients from secondary literature. Under 60 inches (152.4 cm) the added part is 0.
• Accepted ranges are height 140 to 250 cm and current weight 30 to 300 kg. These are adult formulas; below 140 cm the Broca result becomes unrealistically small, so shorter heights are rejected. Metric units only.
• Your weight is judged by BMI rounded to one decimal. Outside 18.5 to 22.9, the gap to the nearest edge is rounded up to 0.1 kg.
• Everything is calculated as decimals and rounded once for display, to one decimal.

Examples

A man of 170 cm. These are example numbers.

Method	Math	Result
Normal range	18.5 to 22.9 × 1.7²	53.5 to 66.2 kg
BMI 22	1.7² × 22	63.6 kg
Modified Broca	(170 − 100) × 0.9	63.0 kg
Devine	50 + 2.3 × 6.93	65.9 kg

Add a current weight of 70 kg and the BMI is 24.2, so about 3.7 kg to lose to reach the normal range.

Good to know

This is a rough estimate for reference only. It is not a diagnosis or treatment, so talk to a doctor if you are worried about your health. A simple formula cannot see muscle, age, build or medical conditions. These are adult rules and do not suit children, teens or pregnant women. Looked up 2026-10-04. For the BMI categories themselves, see the BMI calculator.