How accurate are body fat % scales?

I usually check my body fat % a couple times a week and it's pretty consistent, I was just wondering how accurate the readings are. Is it off by 1-2 numbers or way off? I ask because my fat % is a little low for a woman, but i do cardio, pull ups, push ups, & crunches 6-7 times a week. my number usually says 13-14 %

Public Comments

1. From what I have heard, not very. I was told by a doctor that it is impossible for a scale to measure your body fat.
2. like anything else, some are very accurate and some are not. I know they use them on Discovery Health Body Challenge, but I don't know what brand.
3. No, they are pretty useless actually. The numbers can be 5%-10% off!