The cup size ‘G’’ can be different depending on the brand as the European brands that do not carry a DD, mean that their G cup is equal to a F or FF cup in an Australian or UK cup depending on the brand. Although a G cup is the same in theory, in practical terms one G cup in one brand could be a whole cup size different in another brand.
It’s important to note that as the back band increases so does the size of the cup. The G cup of a 16G is bigger than the G cup of a 12G. So in actual fact a 16G is 2 cup sizes bigger than a 12G. So, not all Gs are the same size. The size of the back band actually changes the size of the cup.
Finding a G cup in a mainstream store is almost impossible unless you want a granny bra. In actual fact, at Brava we fit G cups everyday. Many women who have been wearing a G cup are quite often a GG or H cup and have not been fitted correctly. We estimate that most women who visit Brava for the first time and tell us they are a G cup, most would be closer to a GG or H cup. But remember the bra band could be too big, so when we fit a smaller back band on our customers this decreases the cup size too so then the cup size then must go up to compensate.