Dang, something is off there. Scales are calibrated differently, so you can different readings on each one you weigh on. They should be within a few pounds of each other though. Doctors are supposed to calibrate theirs regularly because so many people use them, but many don't. Just stick with whatever scale is your "official" scale to gauge the most accurate rate of weight loss. I would get out a measuring tape/stick and see how tall I am for myself. That is very strange. Someone made a mistake.