BMI Calculator

BMI is a quick screening indicator, not a precise measure of body composition. It does not distinguish between muscle mass and fat mass, so very muscular athletes may have a high BMI while being healthy. For a complete assessment, consult a doctor.

BMI does not consider age, sex, ethnicity, or body fat distribution. It is not suitable for children (use percentiles), pregnant women, the elderly, or athletes. More accurate indicators include waist circumference, waist-to-hip ratio, and body fat measurement.

BMI < 18.5: Underweight. 18.5-24.9: Normal weight. 25-29.9: Overweight. 30-34.9: Obesity class I. 35-39.9: Obesity class II. ≥ 40: Obesity class III (morbid). These values apply to adults; for children and adolescents, age- and sex-specific charts are used.

BMI comes from dividing the weight in kilograms by the square of the height in metres. When the figures are entered in pounds, feet and inches, the conversion happens before the calculation.

Below 18.5 BMI means underweight, 18.5 to 24.9 healthy weight, 25 to 29.9 overweight and 30 upwards obesity. The range reached is shown alongside the calculated value.

BMI is a quick screening figure and does not tell muscle from fat, so someone with a lot of muscle comes out high while being perfectly well. The assessment belongs to a doctor.

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