Body Fat % calculator

I have just done a BF% thing online, and it came up with four results, ranging from 19% to 29%, based on the same measurements, according to the body fat algorithms developed by the U.S. Navy, U.S. Army, U.S. Marine Corp and the YMCA. Does anyone know which algorithm is the most accurate?

None of them. The only way to accurately measure BF is by having a DEXA scan. Here's a portion from a CNN report:

DEXA scans

Upside: Superaccurate. This low-radiation, full-body X-ray, typically used to screen for osteoporosis, computes body composition and the percentage of fat in the body by measuring fat mass, lean mass, and bone mass. "They are the gold standard," says David Freedman, Ph.D., an epidemiologist in the Division of Nutrition, Physical Activity, and Obesity at the Centers for Disease Control and Prevention in Atlanta, Georgia.

Downside: Cost. Unfortunately, if not covered by insurance, a DEXA scan could end up costing you a couple hundred dollars, an expense that isn't necessary, according to Nelson.

Other body fat measurements

Upside: Your wallet won't take such a hit from other more economical approaches. Bioelectrical impedance analysis (BIA), which can sometimes be found at health clubs and involves attaching electrodes to the hands and feet or standing on electrode pads, sends a small electric signal through the body to compute the composition of body fat and muscle mass. Some physicians and health clubs also use so-called skin-fold tests, which use calipers or pinchers to measure the thickness of folds of skins at different parts of the body.

Downside: These measurements are cheaper, yes, but they are also less reliable than a DEXA scan. The BIA is heavily influenced by hydration levels and thus, can be imprecise; depending on the technician, a skin-fold test can be inaccurate too.

If you want to read the full article it can be found here:
http://articles.cnn.com/2009-01-02/health/healthmag.measuring.body.fat_1_bmi-estimate-body-muscle-mass-and-body?_s=PM:HEALTH

Hi Fteale, by any chance can you get your body fat percentage checked today on one of those "Have you checked your weight today" scales? They usually have the body fat option. You might have to bring a pen/pencil and paper. The older machine use to print out sheets. I don't think the new one do now.

You will be able to see what a scale gives you and compare it to the sites.


Me personally, I wouldn't use an online body fat calculator. I rather use a body fat scale or Omron Handheld body fat monitor. I have both and they both give me the same body fat reading.

I don't have time to go and get it done properly. I have small children and am doing a Masters at uni. I don't get time to pee in peace, let alone get out and have a fat scan done.

It is important to me, because I know from past experience when I drop below about 17% BF I stop getting periods, and as far as I am concerned that is not healthy, so I want to know where I am now so I know what I have to play with. I run a fair bit and don't want to make myself ill.

You own a scale? If you can afford the Omron Handheld Monitor. Order it from Amazon.

I don't own a scale. Nor do I want to. I weigh myself about once every 5 weeks when we go to my parents. I don't want to be tempted to weigh in more than that. I was anorexic in my teens and I am not going back there.

Maybe you can still get a Omron Body Fat Monitor. For the machine, you have to put your weight in each time. Since you weigh yourself every 5 weeks, it would be good to get your body fat percentage then to.

Do you know the formula to see how much of your scale weight is from fat and how much is from lean body mass?

If not, this is the formula.

Weight x BF% = Pounds of fat
Weight - Pounds of fat = Lean body mass.

I can help you see what body fat percentage would be good for you and what weight would be a good weight. I would need your weight and body fat percentage to do this. You will need to get your correct body fat percentage.

Accuracy is probably influenced by body shape some.

^ This.

For what it's worth, I did the same tests and Army and Navy measurements were both pretty close to accurate. YMCA one was way off.