If you look up Brassiere Measurement on Wikipedia and read the section on measuring cup size without a bra, well let's just say it can be a bit of an eye opener.
e.g. I have a 40" chest and a 43" bust, which by standard measure should be a B cup, but using the other method I only just get 7" which is a small A.
So if you take that and the craziness of how bras are sized, I'm going to need to get a lot bigger before I fill out the cups of a bra with the correct band.
If you go by underwire size the volume of the cup for a 44A is the same as 42B 40C 38D 36E 34F 32G 30H 28I
Talk about crazy, who came up with this system? I bet it was a man.