Body mass index is a calculation that uses your height and weight to estimate how much body fat you have. Too much body fat is a problem because it can lead to illnesses and other health problems. BMI, although not a perfect method for judging someone’s weight, is often a good enough.
The best way to determine your BMI is to have your doctor do it for you. That way, you’ll know the number is accurate and your doctor can discuss the result with you. You also can figure out your BMI with this calculator.