Just wondering how everybody's calculating their body fat. I'm 5'5" and 110 lbs. Skinny but not muscular, and I want to make sure I'm not "skinny-fat". When I do gain a few pounds, it goes right to my belly. My grandmother was a classic apple shape--big round belly with no butt, skinny little stick arms and bird legs. That's my future if I'm not careful. Thanks!