Man I don't know. I hate to buy shoes without trying them on first. I was lucky that the owner of the
lbs wore same size as me and I liked his SIDIS so I just bought the same thing. Try to try it on somewhere if you can. If not, it is your preference. I like my shoes just right not too tight. I wear a felt insole in mine and that made all the difference. If you buy too tight though you are screwed.
GL