I wear a medium and ordered a medium in this work out top. It is too big all over, the bust (I am a 36C), the arm pits and the length. I am returning it and not getting a small because even if it were tighter, it is too long for me.

If I were to use their size chart, I would need an XL!  No way!

The positives are that is made very well and the neckline has nice detailing.  The pocket is cute, Id probably put any key in it.  If it fits you, its a great deal!