BMI Calculator
Body Mass Index (BMI) is the most widely used indicator worldwide to assess whether a person's weight is appropriate for their height. Calculate it in seconds by entering your weight in kilograms and your height in centimeters. The result is classified into four categories according to World Health Organization criteria: underweight, normal weight, overweight, and obese.
Body Mass Index
Valid for adults aged 20 and over. Not suitable for children, teenagers, or pregnant women.
Publicidad
Ad
How it works
The BMI formula is: BMI = weight (kg) / height² (m²). The result is interpreted using WHO ranges: below 18.5 = underweight; 18.5 to 24.9 = normal weight; 25 to 29.9 = overweight; 30 or above = obese. This formula is valid for adults aged 20 and over. For children and teenagers, age- and sex-specific percentile charts are used.
Publicidad
Ad
Preguntas frecuentes
- What is BMI and what is it used for?
- Body Mass Index is a measure that relates weight to height to classify whether a person is underweight, normal weight, overweight, or obese. It is a useful population-level screening tool, though it does not directly measure body fat percentage.
- Is BMI the same for men and women?
- Yes, the formula and ranges are the same for both sexes according to the WHO. However, women tend to have more body fat than men with the same BMI. Some health professionals adjust the interpretation by gender for more precise analysis.
- What is a healthy BMI?
- According to the WHO, the normal range is between 18.5 and 24.9 kg/m². Below 18.5 is considered underweight; between 25 and 29.9, overweight; and 30 or above, obese. Within obesity, there are grades: I (30–34.9), II (35–39.9), and III (40 or above).
- Does BMI work for athletes or very muscular people?
- Not precisely. BMI does not distinguish between fat mass and muscle mass. A very muscular person may have a high BMI without having excess fat. For athletes, it is more useful to measure body fat percentage through bioelectrical impedance or DEXA scanning.
- Can I use this calculator for my child?
- Not directly. For people under 20, BMI is interpreted using age- and sex-specific percentiles, not the fixed WHO adult ranges. A BMI of 23 may be normal for an adult and overweight for a 10-year-old. Consult a pediatrician for a proper evaluation.