Any one have one of these? Any idea how accurate they are?

Mine does it, but I have now way of knowing if it's right. It tells me I'm really fat, but I knew that already. But if I do the math, it also tells me I have a lot of lean, 113 lbs of it. More math tells me that to be in healthy body fat percentage range, I need to weigh 143-168. Wouldn't that be nice! But all this math is based on what my scale is telling me right now. I guess I'll just have to see if it holds steady as I lose.

Pretty inaccurate! They can be off by quite a bit. Yes, at 210lbs and 5'2, you will have a lot of lean mass from carrying your weight. If you lose the fat, eating high protein and lifting weights to preserve your muscle, then your body composition at 143-168 would be a lot 'fitter'/'athletic' looking than the same girl losing the same weight who did not eat high protein and did not lift weights. Muscle preservation is very important for body composition, whereas many people completely ignore this and focus only on losing #'s on a scale

Yes quite inaccurate. They can be useful to tell a story via data over time but that is all they are good for.