The problem with a lot of jeans is they don't make 36 inseam. And since everything is from the land of almost right you just about have to try them on to see if the size is right.
Ha! You oughta be a fatboy trying to find things that fit. According to the clothing manufacturers, the fatter you are around the waist, the shorter your legs are. However, the bigger the shirt, the longer the arms. I swear, if we were built the way their clothes are sized, we would look like this...