[ValorPhoenix]

Depends on the bra manufacturer you're going by. Typically speaking, DDD should be the same as F, or two cup sizes bigger than D, which is two inches more bust circumfrence.  

[MrHHH]

Honey, I would think it would be easy for a woman to find out. After all, you are supposed to go bra shopping.

I think a DDD is supposed to be an F cup.
 

[RandomX]

Yes, DDD is an F cup. A good size *grin*

[MasterDragonfly]

Bra sizes aren't as universal as we could hope for.  Especially at an international level.  My girl is from New Zealand, and in her experience there really is a sequence which goes, "A, B, C, D, DD, E, EE, F, ...".  *sigh*

When in doubt, I just defer to this site:

http://www.plussizebras.org/

I also like Dr. Pechter's technique for measuring bra sizes.  You should be able to Google his name for a reference.  

Jim{ruby}