The scales do the calculation sending an electric pulse through your feet (you do not feel it) and based on the time it takes to get back, considering your height age and weight it, it derives the number. Super accurate, no, but I do believe that is exactly what the hand held body fat machines do that doctors use. My scale does water percentage and muscle, each one has its own algorithmic science behind it. I would like to believe its close... but perhaps I'm being defensive because I WANT to believe my scale lol. I would ask a professional who is not biased.... guess I should as well.
Goal #1: Get under 300 lbs
Goal #2: Size 22
Goal #3: Size 20
Goal #4: Size 18 by Spring 2012