What size skate shoe should I order?

I'm about to order some new skate shoes from online. Probably either DC, Vans, Roxy, or one of those companies. I'm usually a 10 in shoes, but the other day I tried on my friend's Vans skate shoes and they were a size 9 and they fit me perfectly, they were even a little loose. So when I order my shoes from offline, should I get a 9? Or a 10 just to be safe? I'm not sure./: