This just about fit when I was wearing a 30JJ in most brands, and a 30J in Alexa/Olivia/Marcie. Truthfully, I wasn't fully scooping and I couldn't quite fill the bottom due to some orange-in-glass (too-small cups, not enough depth), and would have really needed a 30JJ. So I'd say to go for a cup up from Alexa/Olivia/Marcie size. This bra seems to work for a variety of breast types, both FoT and FoB.
Aside from needing a bigger cup, my main issues with this bra are the straps, gore and band. The straps are wideset, so they can irritate and slip off my shoulders a lot - not the best for narrow shoulders. The gore is quite wide, which is bad for my close-set boobs. Finally, the bra has a partial band rather than a full, so the wires stretch a lot more than they normally would, which makes the wide gore even worse, and the band runs about half a bandsize loose in the higher cup sizes. Not the best bra for close-set boobs or narrow shoulders.