How do they tape you at meps, whats the formula they use to tell you BFP?

I know how they tape you but how do they figure out your body fat percentage? im 22 72" tall 15.5" neck and around 40" waist. . . i want to know what they would put me at how they would get it and if they would round my neck up since its at .5 and give me a 16" neck and if they will round my waist down if im at 39.4" waist. thank you.