[ruch]

If your under bust measurement is a 29, then your band size should be 30. 34B's sister sizes (meaning the cup sizes are the same) would be 32C and 30D. Even though they have different letters, the cups are the same size as a 34B, but the band would fit you more properly, and also other aspects of the fitting of the bra. From your measurements (and photos), I also agree you sound like a 30DD (sister size is 34C, but that is a huge band size for you). You have 5" difference in between your under bust and bust, and the way you usually get your cup size is 1" = A, 2" = B, 3" = C, 4" = D, 5" = DD. Your proper band size is your under bust measurement, rounded up to the nearest even number (so, 30). That's why you should probbaly be wearing a 30DD. I used to think I fit a 32A (which I wore for years!) but when I really looked at the fitting, I realized that even if the cups fit me, the bra did not fit at all. For example, my bra strap rode up in the back (a sign that the band size is too big), and I think I have some breast tissue migration around my armpits and upper back as a result - and it makes no sense for me to have fat around there since I am thin all over (so this is why I think it may be breast tissue migration). I am actually a 28C or 28D so I am going to try to find bras in that size and see how it improves..

Check out this website:
http://www.venusianglow.com/2008/04/does-this-bra-fit-how-do-i-tell.html

About breast tissue migration:
http://www.venusianglow.com/2009/09/get-rid-of-armpit-rolls-in-5-seconds.html

The whole website is very informative so browse through the pages if you have some time.
http://www.venusianglow.com/2008/04/bra-matrix.html