Body Mass Index (BMI) – is considered a more accurate tool than body weight alone in order to assess potential overall health and risks associated with being overweight. Lean body mass (muscle) weighs the same as fat, but takes up 2/3rds less space on your body. So you can see why a person with a lower BMI or lower Body Fat % looks slimmer than a person of the same height and weight, but with a larger % of body fat makeup. Remember that BMI alone should only be used as a guideline and is not 100% accurate. Make sure that you are getting your body fat % measured either using an impedance scale at home or get the help of a fitness professional utilizing body fat skin fold tests to get the best accuracy of your overall body fat % and health. Calculate your BMI at our site today with your free fitness profile!