BMI (Body Mass Index) is a practical indicator that helps you interpret your weight relative to your height. Use the calculator below, then read the guide to understand the results.
BMI CALCULATOR
What is BMI and how is it calculated?
BMI is calculated using the formula weight (kg) ÷ [height (m)]² . For example, for a weight of 80 kg and a height of 1.80 m, BMI = 80 ÷ (1.80×1.80) = 24.7.
By looking at the value, you can see which class your weight is closest to: "underweight, normal, overweight, obesity" according to your height.
Adult BMI classes (WHO)
| BMI | Comment |
|---|---|
| < 18.5 | Weak |
| 18.5 – 24.9 | Normal |
| 25.0 – 29.9 | Overweight |
| 30.0 – 34.9 | Obesity Class I |
| 35.0 – 39.9 | Obesity Class II |
| ≥ 40.0 | Obesity Class III |
In children and adolescents, BMI is assessed using percentile tables for age and sex; the ranges above are for adults.
Limitations of BMI
- It doesn't differentiate body composition: it doesn't know the ratio of muscle to fat. In very muscular individuals, a high BMI doesn't necessarily mean excess fat.
- It is not sufficient alone for the elderly, pregnant women and in some clinical situations.
- It does not measure fat distribution (abdominal circumference, etc.), so it is useful to look at it together with waist circumference.
Why is waist circumference important?
Central adiposity is associated with cardiometabolic risk. Commonly used thresholds are ≥94 cm (high risk ≥102 cm) for men and ≥80 cm (high risk ≥88 cm) for women . If you enter gender and waist circumference into the calculator, you'll see a badge and a short assessment based on the thresholds.
Frequently asked questions
Does BMI indicate a healthy weight?
It's a general indicator; it doesn't explain muscle mass and fat distribution alone. Waist circumference is only significant when combined with blood tests and a physician's evaluation.
Is BMI calculated differently for men and women?
The calculation and adult classes are the same. However, waist circumference thresholds vary by gender.
What is the target BMI range?
The general target range is 18.5–24.9; age, sport, and clinical conditions may alter the individual target.
