BMI calculator
Free online BMI calculator. Calculate your body mass index, BMI calculator online with WHO reference table and visual indicator.
WHO Reference Table
| Category | BMI |
|---|---|
| Underweight | < 18.5 |
| Normal weight | 18.5 – 24.9 |
| Overweight | 25 – 29.9 |
| Obese class I | 30 – 34.9 |
| Obese class II | 35 – 39.9 |
| Obese class III | ≥ 40 |
How it works
- 1
Choose the measurement system
Select metric (kg and cm) or imperial (lbs and ft/in) based on your preference.
- 2
Enter weight and height
Fill in the two fields with your values: BMI is calculated automatically in real time.
- 3
Check your category
The result shows your BMI with the corresponding WHO category (underweight, normal, overweight or obese) and a colored visual bar.
FAQ
How is BMI calculated?
BMI is calculated by dividing weight in kg by the square of height in meters: BMI = weight / height². For example: 70 kg / (1.75 m)² = 22.86.
Is BMI reliable?
BMI is a general indicator but doesn't account for muscle mass, bone structure and fat distribution. Muscular athletes may score as 'overweight' while being fit.
What is the ideal BMI?
According to WHO, the normal range is between 18.5 and 24.9. Lower values indicate underweight, higher values overweight or obesity.
