BMI Calculator

BMI (Body Mass Index) is calculated as weight in kilograms divided by height in meters squared. It's a widely used screening measure because it only needs height and weight, but that simplicity is also its main limitation: BMI can't distinguish muscle from fat, so it can misclassify very muscular people as overweight and underestimate risk in people with low muscle mass.

The World Health Organization's standard adult categories — underweight, normal weight, overweight and obese — are the ones used here. These thresholds were developed from population-level data and are less reliable for children, teenagers, pregnant people, older adults and elite athletes, whose body composition differs from the general adult population the categories were built around.

This tool is a screening estimate for general awareness, not a diagnosis. If you have concerns about your weight or health, a healthcare provider can assess body composition and health risk far more accurately than BMI alone.