BMI calculator
Calculates body mass index from height and weight. Read the caveat before you use the result: BMI frequently gives the wrong answer for someone who trains.
Result
Fill in the fields and the result appears here.
WHO range
| WHO range | Range |
|---|---|
| Underweight | < 18.5 |
| Normal | 18.5 – 25.0 |
| Overweight | 25.0 – 30.0 |
| Obese | ≥ 30.0 |
How it is calculated
BMI is weight divided by height squared. It was developed in the 19th century for population statistics, and that is still what it does best: screening large groups.
What it tells you about one person is limited, because it does not separate muscle from fat. Someone with a few years of consistent training routinely lands in the "overweight" range. The reverse happens too — a normal BMI with a high body fat percentage passes the screen entirely.
It is equally blind to where fat sits. For metabolic risk, waist circumference and waist-to-height ratio are more informative than BMI.
BMI is here because people search for it. If you are making decisions about body composition, body fat percentage and circumference measurements are far more useful — both are on this site.
Sources
- World Health Organization (2000). Obesity: preventing and managing the global epidemic. WHO Technical Report Series 894.
- Rothman K.J. (2008). BMI-related errors in the measurement of obesity. Int J Obes 32: S56-S59.
You have the number — now comes the decision
Comparing these numbers against weekly data and revising with a stated reason is the actual work. That is how online coaching runs here.