Your result
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How it is calculated
Body mass index divides weight by the square of height:
BMI = weight (kg) ÷ height (m)²
Pounds and inches are converted exactly (1 lb = 0.45359237 kg, 1 in = 2.54 cm) before calculating. The result is shown to one decimal place, and the category is read from that rounded value so that the label always matches the number displayed.
| BMI (kg/m²) | Category |
|---|---|
| < 18.5 | Underweight |
| 18.5 – 24.9 | Healthy weight range |
| 25.0 – 29.9 | Overweight (pre-obesity) |
| 30.0 – 34.9 | Obesity class I |
| 35.0 – 39.9 | Obesity class II |
| ≥ 40.0 | Obesity class III |
The weight range shown in your result is the range that gives a BMI from 18.5 to 24.9 at your height: 18.5 × height² to 24.9 × height².
Limitations
- BMI is a screening measure, not a diagnosis. It does not measure body fat directly and cannot tell muscle from fat, so very muscular people can have a high BMI without excess fat.
- It says nothing about where fat is stored. Waist circumference adds information about abdominal fat.
- The same BMI can correspond to different health risks across ethnic groups. A WHO expert consultation noted higher risk at lower BMI in many Asian populations and proposed additional public-health action points (23 and 27.5).
- The adult categories do not apply to children and teenagers, whose BMI must be compared with BMI-for-age growth charts, nor during pregnancy.
- The weight range is a population reference, not an individual target weight.
Sources
- World Health Organization. Obesity: preventing and managing the global epidemic. WHO Technical Report Series 894. Geneva: WHO; 2000. Read the source (opens in a new tab)
- WHO Expert Consultation. Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet. 2004;363(9403):157–163. Read the source (opens in a new tab)
- World Health Organization. BMI-for-age (5–19 years) growth reference. Read the source (opens in a new tab)