Q: I looked at my wife’s bra and it says 34B. What size is this when speaking in terms of Small through X-Large?

Answer:

A 34B is typically a Medium by most standards. You need to make sure, of course, with each lingerie manufacturer. When you are looking at sizes pay attention to 

not only the 34B part but the waist/hip area as well. You will want to make sure it fits all the way around and more than likely, the waist/hip area will be the deciding factor because many lingerie pieces stretch. You only really need to zero in on the bust/cup size when you are looking to get a piece of lingerie that has an underwire, is a bra or does not stretch in the breast area.