According to the body fat percentage scale my mother has, I'm at 23.5% body fat. According to the Navy, I'm at 27% body fat. According to the YMCA, I'm at 35% body fat. Does that mean the Navy thinks my weight is acceptable but the folks at the Y look at me and think "obese?" Because that seems silly.

Does anybody here measure their weight loss using body fat percentage? If so, what method do you use to measure? Do you find that it is a useful way to measure progress and set goals?

I don't use this, but i believe most just take a measure of your height divided by your weight. Does the YMCA use one of those arm band or hand held things? It would be hard to imagine you are obese if you only weight 132 lbs. I am the same height and I believe the overweight category starts around the 140's...I don't even know where obese would start, maybe 160's?

Are they all using the same kind of tool to measure this?

I get the same random BF %'s. I like the navy's personally, but just because it's in the middle. I most dislike the handheld thing. I've heard the scale you stand on measures your lower half, the hand held measures the upper half and I'm not sure about the navy scale.

The Navy method (assuming you are talking about PRT measurements) uses an algorithm derived from simple tape measurements and your height. It has been validated to plus or minus 1.5% when compared to hydrostatic weighing (I was involved in this research in the late '90's/early '00's). It does not rely on calipers or your hydration status (unlike bioimpedance methods). This is the most accurate way to determine body fat percentage other than hydrostatic weighing or autopsy.

I find it more valuable to use BF% to track a gaining/losing trend rather than as an absolute number. It is especially valuable when you are no longer losing weight, but are still changing your body composition with strength training. I hope this helps.