Calculating BMI is the best and quickest method for assessment of weight categories that may lead to health problems. All you need to know is your height and weight. Keep the calculator in your gym bag or bathroom and the next time you weight yourself, get your BMI in a snap!
Calculating Body Fat % is simple and accurate using the U.S. Navy's and Department of Defense techniques. Simply measure 2 or 3 sites using the most accurate, easiest, and consistent method in the world. Tens of thousands of armed services personnel around the globe are routinely measured for body fat and physical readiness standards using the simplest tool in the world - a tape measure!
Once Tonus calculates your body fat %, it will then provide you with your lean body mass and then BMI. Weight alone is not a clear indicator of good health because it does not distinguish between pounds that come from body fat and those that come from lean body mass or muscle.
Lean Body Mass is the best way to gauge your muscle mass improvement through working out and is your total weight less your body fat weight. It is good to know this number as you can track pounds (or Kg) of muscle that you are adding.