Quote Originally Posted by Nanook View Post
If you are a 42Reg then I'd order a 42Reg. English sizes and U.S. sizes are the same. Italian too. If you have a large gut and 40"-41" chest then many Italian and English 42s won't fit. Many American made jackets (such as those from Oxxford) won't either. Going to a 44 is not the solution. Going to a tailor and looking to either made to measure or bespoke is the solution. A good tailor can tweak a ready to wear jacket to make it fit as if made to measure--- why some RTW jackets such as those from Brioni, Kiton or Oxxford are more highly regarded by top-tier tailors than many a bespoke--- but only if its a ballpark fit. I'd look to the fit of the chest, the waist and especially the sleeves.
I'm only speaking from my experience with the 3 different places we order jackets from over in Scotland. I've ordered for people that insist they are a 42 in their jacket and it's arrived and is much more "snug" than they'd prefer. I'm a 42 suit jacket (when I WORE a suit) and I'm a 44 kilt jacket.

I do agree that the only way to get a perfect fit is to get it MTM (made to measure) or get an "off the peg" jacket tweaked by a tailor. Either way, that would be more expensive than ordering a jacket just "off the peg".