BMI + estimated size calculator
Calculate your Body Mass Index (BMI) and get an estimate of your clothing size.
BMI (Body Mass Index) is an indicator used by the WHO to assess an adult's build. The formula: BMI = weight (kg) / height²(m). A value between 18.5 and 24.9 corresponds to a normal build by international criteria.
BMI is a population indicator: it gives a general indication but does not account for muscle mass, gender or age. A very muscular athlete can have a high BMI without being overweight. For a precise individual assessment, consult a health professional.
BMI categories (WHO)
| IMC (kg/m²) | Category |
|---|---|
| < 16,5 | Undernutrition |
| 16,5 – 18,4 | Underweight |
| 18,5 – 24,9 | Normal weight |
| 25 – 29,9 | Overweight |
| 30 – 34,9 | Moderate obesity |
| ≥ 35 | Severe obesity |
Frequently asked questions
What is the BMI formula?
BMI = weight in kg / (height in metres)². Example: 70 kg / (1.75 m)² = 70 / 3.0625 = 22.9. A value between 18.5 and 24.9 corresponds to a normal build per WHO.
Is BMI valid for everyone?
BMI is a statistical indicator suited to adults 18 to 65. It is not reliable for children (use pediatric growth curves), pregnant women, elderly, or muscular athletes.
How do I interpret my BMI?
Below 18.5 = underweight. 18.5-24.9 = normal. 25-29.9 = overweight. 30-34.9 = moderate obesity. 35-39.9 = severe obesity. 40+ = morbid obesity.
Can BMI estimate my clothing size?
Our tool gives an estimate based on BMI + height. For an accurate size, measure your chest or waist. BMI estimate is useful for gifts when you cannot ask.