Originally Posted by Lord Asquith
You really want to try these on and buy them at a shop. But if you want to guess then your 11.5 D would be like a C&J 11 G if the model you want even comes in that width. Almost all C&J shoes are an E width (a US C) which is why people go for a full size difference between Eng and US shoes. It's not the length because there's only 1/2 size diff. but the width.I'm a 11.5 B (US) and the C&J 11 E fits perfectly so that E is like a US C.
Fascinating... everything else I've read suggests that C&J "E" is simply their designation for "medium width", and thus roughly equivalent to other English shoemakers' "F" and American "D". I've never worn C&J shoes, so I can't offer any personal evaluation, but the vast majority of shoes in their catalog are either "E" only or "E" + something else, which would be odd if that really was a narrower-than-normal size.
Logically, US 11.5D would be 10.5 or 11E in C&J sizing (depending on whether one believes the size offset to be 1/2 or 1).
(Of course, "you really want to try these on" is obviously excellent advice!)