It is hard to believe that you are only 28% BF at 325lb. to be 0% fat at 234lb, even for a 6'5" man, will put you in mister univers category/Arnold type category...

The only accurate why to measure BFI is an emersion test where you get imersed in water and the measure the amount of water displaced, and based on you weight they can calculate your BF. All otehr measurment methodes are only good to measure progress but not absolute BFI..

A good estimate would be to figur out what should your weight be for your hight and shape (muscles) and the rest must be fat..

Ex. I weigh 225lb, I am 5'11", I am built, so I should be 160 at 0% BF. which means I carry 65lb of fat (yeeeck) which is 28% BF..