This makes sense, because after all the tape is measuring only across the center of the breasts, and so the bra size calculator doesn´t take into account the volume of the entire breast.
How far is this chart is correct ? I can´t really say, as I am the owner of UUs, so no size adjustment for me. I´m guessing it´s more of a general guideline than a firm rule. One thing I´ve noticed is that the firmness of breasts can change the fit: unfirm breasts compress easily, and often need up to one cup size less than the calculator says.
What do you think of breast shapes & cup sizes ? Do these guidelines hold true for you ? What about the cute Thai poster on the top ?