I’m not a fan of BMI, since it would give a 5’9 220lb football player (say, a fullback) the same BMI as mine.
I found this long time ago, and I’m guessing this is a linear regression best fit formula.
So, if one’s actual body fat percentage is way off the best fit, then it won’t work. However, it should work on a relative basis, and one should understand what is necessary to lose body fat.
In my range, dropping an inch of waist, without lowering weight, lowers BFP by about 2%.
Lowering my weight by 5 pounds, without lowering my waist size, raises my BFP by 0.8%.
so, determine how to do it: eat less, workout more. Done!
Men (Imperial measurements):
F1 = Weight * 1.082 + 94.42
F2 = Waist * 4.15
Lean Body Mass = F1 - F2
Body Fat Weight = Weight - Lean Body Mass
Body Fat Percentage = Body Fat Weight / Weight
I have it in an Excel file for ease of use. Today for me: 22.2%
Women’s calculation is more complicated, 'cause amirite?
F1 = Weight * 0.732 + 8.987
F2 = Waist * 0.157
F3 = Hips * 0.249
F4 = Wrist / 3.14
F5 = Forearm * 0.434
Lean Body Mass = F1 - F2 - F3 + F4 + F5
Body Fat Weight = Weight - Lean Body Mass
Body Fat Percentage = Body Fat Weight / Weight
There are web sites that use this, bt don’t show the formula, 'cause math.
My source, from my Internet Explorer Favorites that were not copied to my Chrome:
https://www.bmi-calculator.net/body-fat-calculator/body-fat-formula.php
But I’d like to know how they concluded these betas, and what the confidence range is.