Using their measurement chart, you won't go wrong! I'm 34dd chest, 30" waist, 5'5" tall, and ordered the recommended size medium, and it fits perfectly!! Normally, I'd order a large,  but because of the 'gathered ' design in front,  if you go up a size,  it might fit baggier than you want. Stay within the chart, & it'll look perfectly tailored to you. I'm very happy with the fit, comfort, & look of this shirt!  It sits just past my jeans and doesn't ride up. It hides all my imperfections, and accentuates my good curves! I wish I bought one sooner!! I bought mine in purple, and might be ordering more in other colors!