Cups sizes are relational but a C cup for example will have a different volume (that's a bit of a clinical word!) depending on the band size. A 32D holds the same volume as a 34C, a 36B, a 38A etc.
I was a 42E when I started Lipotrim and am currently a 36F - but effectively my boobs have less volume despite the cup size being an F now (if that makes sense)!
My boobs are the only place I am slightly concerned over - I have the "two (rather ample) satsumas in the bottom of a pair of tights" look at the moment which is not attractive!