Inputs (may use fractions):
Height:	feet inches
Weight:	pounds
Body fat:	%
Results:
Fat-free mass:	pounds
FFMI:
Normalized FFMI:	(this is the number to compare with others)

Inputs (may use fractions):
Height:	meters
Weight:	kilos
Body fat:	%
Results:
Fat-free mass:	kilos
FFMI:
Normalized FFMI:	(this is the number to compare with others)

(Defaults taken from United States male averages here and here. Note however that the study was done on competitive bodybuilders with relatively low body fat percentages; it doesn't work for average individuals.)