ive asked this before but never had a good answer. i wear a 11.5F in most shoe makes however there is usually some room in the width. would a 12E work in C&J? they make very few shoes with an F width... An 'F' fitting is used by most shoe makers as their standard/normal width fitting. C&J are anomalous in this respect and use 'E' to denote their standard/normal fit, an 'F' fitting C&J is actually their wider fitting shoe. In light of the above I would guess, generally speaking, if you're an 11.5F in most shoes, you'd also be an 11.5F in C&J; not a 12E. Now if you are an 11.5F in most of your shoes and they leave you some extra width you could consider getting a C&J 'D' fitting which is narrow. But you'll have to consider that some of the C&J lasts, such as 360 & 348/358 do run narrow, so it's not uncommon for folks to drop down a half or even a full size in particular narrow shoes. Hope that helps.