+1what i said had nothing to do with what a scale says.
But i like how people instantly jump to that.
These suits/jackets are made for someone with a fairly low body fat percentage. I have a lot of upper body strength. My arms are not small, nor are my shoulders or neck.
I have a 44" chest. I also have a size 44 joe rocket jacket, and if it wasn't for being overweight it would fit perfectly. The only place on the jacket that doesn't fit absolutely perfectly is my stomach.
Thus, if you are like me and in less than perfect shape (and this is not debatable and does not "depend on your definition" because this has nothing to do with "weight") then you should order a size larger. This will allow you some stomach room, though the rest may fit less than ideally.