Calculate BMI Using Metric Units
BMI (Body Mass Index) gives a quick weight-for-height assessment. The metric formula is: BMI = weight (kg) ÷ height (m)². Enter your measurements to see your result.
BMI categories (WHO standard)
| BMI | Category |
|---|---|
| < 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| ≥ 30.0 | Obese |
What BMI doesn't capture
- Muscle mass — athletes score 'overweight' despite low body fat
- Fat distribution — visceral fat (around organs) is more dangerous than subcutaneous
- Age and sex differences in body composition
Frequently Asked Questions
What is a healthy BMI?
18.5–24.9 by WHO standards. Context matters — see your doctor for a full health assessment.
Is my data stored?
No. BMI calculation runs in your browser; height and weight are never sent anywhere.