I ordered this item a size up because I had to do that for the vest I bought a number of years ago. If you actually fill the pockets provided, you'll definitely need that extra room. I find this jacket great for air travel because there are items I want to use on the plane but don't want to have to dig around in my carry-on for them throughout the flight. So I "preload" my pockets before I ever go through security (since I have to take it off for security anyway). I buy water once I get through security, and that plus my iPad, iPhone, hand sanitizer, hand cream, IDs and credit card (for food purchases on the plane), etc., are all accessible from my jacket! It's just the right weight for the cold airplanes, too!