I have been using an old "dial" scale ever since I started on SP. It never records right....you can get on & it would give one reading, & after getting off & on again it would register another reading. I bought a new digital scale a couple of days ago. The new scale says I weigh 8.4 lbs. more than the old one!! It seems to be closer to the doctor's scale so is probably right, but it sure did hurt to change my weight on my SP weight page.