So I created a preliminary BF% calculator that takes and average of the three methods. How ever every time I use the Formula that is provided for the 4 site equation it gives a very different answer from what all the calculators show online. Excel is doing the math right I checked it. Do the online Calculators go from BMI to BF% is that the Problem. It is rather large difference 5% in fact. Even some sites that have calculators and gave the formula right below that return me at 20.1% body fat same thing for how ever when I plug my numbers into the formula i get 25%.Formulahttp://www.topendsports.com/testing/density-jackson-pollock.htm Calculatorhttp://www.linear-software.com/online.html#Note I attached the excel spread sheet if any one wants to use it How ever the formula is for men. That said if you are a girl the math is basically the same you just need to change some of the set numbers and where you get the measurements from.