If yur friend did your BF with a pair of GNC calipers, or one of those $125 plastic electronic devices, or one of those websites, none of them are going to be correct. need a P.T. to do it correctly with at least a 5 or 7 point skin fold test with a professional pair of clipping calipers. The other methods are too fat off to be accurate. Teh online calculator told me my sister was 31%BF! She is 5'4" tall, 102# with a 21 " waist and a 6" wrist. I will bet a bullet in y head she is no more than 12-15% and for a woman that is actually really low!
So do not go by 17% If your buddy did the reading unless he has a good set of skin fold calipers and is usin the 5 or 7 area skin fold test