Navy womenįrom body circumferences and height. Navy men from body circumferences and height. The initial research behind the Navy calculation calculations can be found by Googling either:
They appear to be accurate within approximately 3%. People with uncharacteristic fat distribution would also have skewed results. Or, if a female had muscular thighs, but a weaker upper body and neck (typical of runners and dancers), the equation might overestimate her body fat. For example, if a male only did exercises that beefed up his neck without adding much muscle to his torso, the equation would probably underestimate his body fat. If the method is accurate within 3%, it must work pretty well for most people, but there are obvious ways the results could be skewed. If your neck circumference increases more than your waist circumference, the assumption is that the increase in your waist was due to muscle, not fat. The underlying assumption seems to be: if you have a larger neck girth, you have more muscle, bigger bones, etc., which shouldn't be counted as fat. Maybe this is because necks don't usually have that much fat. I think neck circumference is being used to correct for your lean body mass so you don't get punished for having big muscles and bones. You'll also notice that neck circumference is actually subtracted, so it makes sense that gaining more girth in your neck than your waist would cause a decrease in estimated body fat. This makes sense since these areas correspond to primary areas of fat deposition for each sex. If you check out the first term, you can see that waist and waist/hip measurements are used to estimate body fat of men and women respectively. The second term probably corrects for height (so that tall people don't get punished for have proportionate girths), and the last term is probably an experimentally-justified constant that corrects the result of the equation to it's as close as possible to actual body fat levels. However, this estimate lacks precision and accuracy, so it needs to be corrected. The first term probably gives you a an estimate of body fat based on a couple circumference measurements. I couldn't find a site that actually explains these equations, but I can make some educated guess about the rationale behind them. Was this built into the Navy algorithm? Does this make it inaccurate?Īccording to WikiHow, the Navy's Body Fat calculation formulas are as follows (measurements in cm): I understand I'm being nit-picky here, as it is telling me that over the past two months I've lost about 4% (coming up on 5%) in BFP, but wouldn't my waist have more weight in the calculation of what my body fat is doing than my neck? The way it is now it seems kind ass backwards, pardon the french. On the other hand, if my waist measurement stays the same (which indicates no change), and my neck measurement decreases by 1/2 inch, my BFP is calculated as gaining a half a percentage point. If my waist measurement increases size 1/8th of an inch (which would indicate a gain of BFP), but my neck measurement increases by 3/8ths of an inch, then my BFP is calculated as losing.
It's done it's job as far as telling me that I'm loosing body fat and gaining lean muscle in it's place, but I still wonder how accurate it is and can be.įrom everything I've read on the net, the general consensus is that it's accurate to within 3% of what Hydrostatic Weighing gives you, but I've noticed something about it's output, namely that my neck measurement has more of a (reverse) hold on what my BFP is than my waist measurement does.
Ymca body fat calculator skin#
Make sure the tape is flat against your skin and even from front to back.
Note: We recommend having someone take your measurement if possible. We’ve provided instructions to ensure you get a proper reading of your waist circumference.
Ymca body fat calculator how to#
To get the most accurate body fat percentage estimation, it’s very important that you understand how to take a correct waist measurement. There are may resources on the internet that can help you to get the most accurate reading. You want to take your height measurement with shoes off, feet together, and standing close to a wall.
Most people have an idea of their height although it’s common to under or overestimate. Note: Woolcott and Bergman (2020) propose RFM cut-offs of 40% for females and 30% for males to diagnose obesity and higher mortality risk.