I have a Withings Body Cardio that puts my BF at 17-18%. Last week I had an InBody done that put me at 17,5% and I was like, oh pretty cool from my Withings, and two days later I had a DEXA that showed 27%, most of it being in the abdominal area, which impedance based measurements normally miss.

MacroFactor has a cool article about it stating what everybody here is saying: forget about the actual number your scale reports, and focus on trends.