Good hat but sizes run a little large. I measured carefully,used sizing conversion chart and ended up being right between a medium and large. I ordered a large because I thought I could size it down a bit by tucking a felt strip inside the sweatband. That would be better than getting one too small with no way to adjust. However, the large size was too big to size down by that method. TJ Vogue was great about exchanging for the smaller size and fast too!  No charge for shipping the replacement medium size to me either. Even the medium does not fit tightly at all but I don't think it will need any felt added to size it down.
A really nice hat but order a bit smaller than the charts indicate. It's soft, crushable felt and has some give in it, so it will fit better in the long run if. It's snug to begin with.