BMI (Body Mass Index) is a widely used screening tool to categorize weight relative to height. While it has limitations, it's a useful starting point for understanding your health.
The BMI Formula
BMI = weight(kg) / height(m)²
For example, if you weigh 70kg and are 1.75m tall:
BMI = 70 / (1.75 × 1.75) = 22.9
BMI Categories (WHO Standard)
| BMI Range | Category |
|-----------|----------|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obese |
Limitations of BMI
BMI doesn't distinguish between muscle and fat. Athletes often have high BMIs due to muscle mass despite being very healthy. It also doesn't account for age, sex, or where fat is distributed.
When to Consult a Doctor
BMI is a screening tool, not a diagnostic one. If your BMI falls outside the normal range, consult a healthcare professional for a full assessment.
Use our free BMI Calculator to instantly calculate your BMI.