Calculate your Body Mass Index based on your height and weight.
Body Mass Index (BMI) is a simple numerical value calculated by dividing your weight in kilograms by the square of your height in meters. It is widely used as a quick screening tool to categorize individuals into weight-status groups and identify potential health risks associated with being underweight or overweight.
BMI does not measure body fat directly, but it correlates with more direct measures of body fat such as skinfold thickness, bioelectrical impedance, and DEXA scans. Healthcare professionals often use BMI as an initial assessment alongside other diagnostic tools.
These categories are based on guidelines from the World Health Organization and are intended for adults aged 20 and older. Different thresholds may apply for children, adolescents, and certain ethnic groups.
While BMI is a useful starting point, it has significant limitations. It does not account for muscle mass, bone density, age, sex, or overall body composition. For example, athletes and muscular individuals may register a high BMI despite having low body fat, because muscle tissue weighs more than fat tissue per unit of volume.
Similarly, older adults who have lost muscle mass may have a normal BMI while carrying a higher percentage of body fat. BMI also does not indicate where fat is distributed on the body, and abdominal fat is generally considered a greater health risk than fat stored in other areas.
Body fat percentage is a more accurate indicator of health and fitness than BMI alone. While BMI uses only height and weight, body fat percentage accounts for how much of your total weight is actually fat versus lean mass such as muscle, bone, and organs.
Two people with the same BMI can have very different body fat percentages and therefore very different health profiles. For a more detailed assessment of your body composition, try our body fat calculator, which uses the U.S. Navy method to estimate your body fat percentage based on circumference measurements.