Right, if you are cut and showing 20% with this device its probably wrong. For example, a friend of mine is the physical fitness coordinator at women's prison, and he brought home a very expenstive bio-impedance device from work to test out, and we both used it. I had been calipered at 12% a week before, but was 28% on this device. My friend had been dieting for a couple of months (he is an ecto), and was the leanest he had ever been. He had viens running though his abes, with very deep abes, obliques and intercoastals. I would have put him at around 6-7%. He was 14.5% on this device.