Body Fat Rate formula:
Female : BFR = (Actual weight-(0.82*Standard weight))*100/Actual weight
Male : BFR = (Actual weight-(0.88*Standard weight))*100/Actual weight

For Example: 5 ft 4 inch, 132 lbs
BFR = 33.05 %
Result = Severely
Suggest = 106.5 ~116.3 lbs

Of course, the human body is very complex. BFR figures are reference values