What size should I get if i wear an 11...
What size should I get if i wear an 11 shoe size in Nikes?
Honestly, I wouldn't suggest gnabbing a set of boots without truly knowing how they fit your feet, I would run to a gear shop and try on boots until I found where my feet belong and then order them. Nothing is worse than having a trip to the snow cut short by killer feet pain. I've never bought boots online for that reason.
Try an 11 at first and if they don't fit try send them back and try a size up or down.