I wear a size 12 jeans and size large Tshirts.  I ordered this in XL and had to max out the ties in the back to squeeze into it.  I also noticed that where the left and right side meet in the middle, it does not dip down but rather points up. I am a 36C so wasn't expecting this.

Super easy return - no questions asked - free return shipping.  So great company but I didn't like this style.