BMI Calculator – Body Mass Index
BMI = weight (kg) ÷ height (m)². Calculate your index and understand what it really means.
The Body Mass Index (BMI) is the most widely used method worldwide for roughly assessing body weight in relation to height. It is not a perfect health indicator, but provides a quick first reference point.
How Is BMI Calculated?
BMI = kg ÷ m²
The BMI formula is simple: BMI = body weight in kilograms divided by the square of height in metres. Example: 75 kg at 1.75 m height → BMI = 75 ÷ (1.75 × 1.75) = 24.5.
BMI Table: Categories According to WHO
| BMI Value | Category |
|---|---|
| < 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25 – 29.9 | Overweight |
| 30 – 34.9 | Obesity Class I |
| ≥ 35 | Obesity Class II+ |
BMI Limitations – What It Doesn't Measure
No Body Fat Percentage
Athletic people with high muscle mass can have a high BMI even though their body fat percentage is low. Muscle is heavier than fat.
No Age or Gender Differences
Women naturally have a higher body fat percentage than men. Older people often have less muscle mass. BMI does not account for this.
No Fat Distribution
Abdominal fat (visceral fat) is more health-risky than fat on hips or thighs. BMI says nothing about where body fat is located.
Better Combined
Waist circumference is an important supplement to BMI. In women >80 cm and in men >94 cm indicates elevated cardiovascular risk.
Calculate and Understand Your BMI
Use our detailed BMI calculators for specific groups or register for a complete body analysis.