Pretty much same as a cameraman 48. They call this a small in Cabourn sizing, but I'm a 46 mallory and cameramen, which I'd call a small.
This is much more a medium IMO.
Shops I spoke to said it came up big. I just couldn't find an XS after Context sold out in less than a day.
So to answer your question, this is really a size 48 in Cabourn sizing. Same as my 48 cameraman. I have a 48 in tweed to wear over my mallory. Otherwise I'm a 46.
Do you understand any of that?...