BMI Calculator
Enter your height and weight to get your body mass index and its WHO category: underweight, normal weight, overweight or obese.
BMI Value
22.9
Normal weight
Underweight
Normal
Overweight
Obese
| Category | BMI Range |
|---|---|
| Underweight | < 18.5 |
| Normal weight | 18.5 - 24.9 |
| Overweight | 25.0 - 29.9 |
| Obese | >= 30.0 |
Note: These calculations are for informational purposes only and do not replace professional tax or financial advice. All information without guarantee.
FAQ
Frequently Asked Questions
What is the BMI and how is it calculated?
BMI (Body Mass Index) is weight in kilograms divided by height in meters squared. For example, 75 kg at 1.80 m height gives a BMI of 23.1, which falls in the normal weight range.
What are the BMI categories?
WHO categories: Underweight below 18.5, normal weight 18.5-24.9, overweight 25.0-29.9, obesity class I 30.0-34.9, class II 35.0-39.9, class III 40.0 and above.
Should BMI be assessed differently for children?
Yes. For children and adolescents, age- and sex-specific BMI reference values (percentiles) apply. In Germany, the Kromeyer-Hauschild reference tables are used. A BMI above the 90th percentile counts as overweight, above the 97th percentile as obesity. For adults, the fixed WHO cut-off values apply.
Guide
What is the BMI Calculator?
The BMI calculator computes your Body Mass Index as a metric for classifying body weight according to WHO categories.
How does the BMI Calculator work?
Enter weight and height. BMI = weight (kg) / height (m) squared. The result is assigned to WHO categories: underweight (< 18.5), normal (18.5-24.9), overweight (25-29.9), obese (30+).
Key Data and Facts
Normal weight: BMI 18.5-24.9. BMI does not account for muscle mass or body composition. For children age- and sex-specific percentiles apply.
Step-by-Step Guide
How to calculate your BMI step by step: 1. Enter your body weight in kilograms: for the most accurate result, weigh yourself in the morning on an empty stomach in light clothing. 2. Enter your body height in meters: e.g. 1.78 m (not 178 cm). 3. Apply the BMI formula: BMI = weight (kg) / (height in m)^2. 4. Read off the WHO category: severe underweight: below 16.0. Underweight: 16.0-18.4. Normal weight: 18.5-24.9. Pre-obesity (overweight): 25.0-29.9. Obesity class I: 30.0-34.9. Obesity class II: 35.0-39.9. Obesity class III: from 40.0. Example 1: a woman, 68 kg, 1.65 m. BMI = 68 / (1.65)^2 = 68 / 2.7225 = 24.98 – normal weight (just barely). Example 2: a man, 95 kg, 1.80 m. BMI = 95 / (1.80)^2 = 95 / 3.24 = 29.32 – pre-obesity (overweight). Normal-weight range for 1.80 m: 59.9 kg to 80.7 kg. Note: the BMI does not take body composition into account. Athletes with high muscle mass may have an elevated BMI without being overweight. For a more nuanced assessment you can additionally measure the waist circumference (risk increased from 94 cm in men, 80 cm in women according to the WHO).
Calculation Example
Woman, 68 kg, 1.65 m: BMI = 68 / 2.7225 = 24.98 (normal weight). Man, 95 kg, 1.80 m: BMI = 95 / 3.24 = 29.32 (overweight). Normal range at 1.80 m: 59.9-80.7 kg.
Sources
Official sources
Calculations are based on applicable German laws and official data:
Full methodology at Methodology.
Reviewed by Konstantin Iakovlev · Last updated:
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