Hiya, ive read they say 125-150cc (may vary) is about a cup size depending on how big or small ur back size is so cause ur only 32, if you go by 125cc per cup size to go up 3 cup sizes you would need 375cc- so the 380 to get to a dd and if you have the 410 youd be slightly bigger so edging on an e. think thats a rough guide anyway.
im a 34b and wanting a dd-e but id go by 150cc a cup size so for a dd, id need 3 lots of 150 so about 460cc to get me to same size! sorry for going on lol but hope that helps x