Please go deep into the listing for measurements and more pictures. This particular blouse is smaller than most of my others.  SO.....
Please go by bust measurements for a good fit 
(these are bust measurments NOT bra size)
100% cotton white blouse. From top to bottom is 30" with sash in back.
Small   32" inches
Medium  38" inches
Large  40 inches
XLarge  42" inches