BMI Calculator: Calculate and Interpret Your Body Mass Index
In short: The BMI (body mass index) is your weight in kilograms divided by your height in metres squared. A BMI from 18.5 to under 25 counts as normal weight according to the WHO. The value is a rough guide for adults and says nothing about muscle mass, body fat or health in an individual case. As of: October 2026.
How do you calculate the BMI?
The formula is: BMI = body weight (kg) / height (m)². Example: 70 kg at 1.72 m gives 70 / (1.72 × 1.72) = 23.7. That is in the normal range.
BMI table: which value is normal?
The World Health Organization (WHO) classifies the BMI for adults as follows:
| BMI | Classification (WHO) |
|---|---|
| under 18.5 | Underweight |
| 18.5 to 24.9 | Normal weight |
| 25.0 to 29.9 | Overweight (pre-obesity) |
| 30.0 to 34.9 | Obesity class I |
| 35.0 to 39.9 | Obesity class II |
| 40.0 and above | Obesity class III |
How meaningful is the BMI?
The BMI is quick to calculate but has limits. It doesn't distinguish between muscle, fat and water. Anyone who does a lot of strength training can have a high BMI with little body fat. Different standards apply to children and teenagers, pregnant women and older people. Waist circumference and the waist-to-height ratio are also helpful.
And then? Calorie needs and plan
If you want to change your weight, a realistic framework helps. First work out your daily calorie needs and take a look at our meal plan for weight loss as well as the basic rules for losing weight. If you want to treat yourself to a short break for a fresh start, you'll find our Juice Cleanse with 3, 5 or 7 days.
Frequently asked questions
What is a good BMI?
For adults, a BMI from 18.5 to under 25 counts as normal weight according to the WHO. Whether a value is right for you also depends on age, muscle mass and health.
How do I calculate my BMI?
Divide your weight in kilograms by your height in metres squared. Or use the calculator above.
Does the BMI apply equally to women and men?
The WHO limits apply equally to women and men. At the same BMI, women have on average more body fat than men.
From what BMI is someone overweight?
From a BMI of 25 we speak of overweight, from 30 of obesity.
Is the BMI meaningful for athletes?
Only to a limited extent. Muscle is heavier than fat, so a BMI over 25 can still go along with little body fat in very muscular people.
Note: This calculator provides guide values for healthy adults and does not replace medical advice. If you have pre-existing conditions, are pregnant or have an eating disorder, please talk to your doctor.
