ToBeInStyle Women’s Long Sleeve Rash Guard Bikini Top & Set - UPF 50+ Sun Protection for Surfing, Swimming & Beach Activities

I am 5'6ish and about 135-140 and I got a medium. It fit pretty perfectly, but just so you know, I have broad shoulders, wide ribs and arms on the slightly bigger/thicker side. The fact that you tie it in the back makes the fit better as you can adjust it. I have very long arms and the sleeves just barely went to my wrists so I think for normal arms they are plenty long enough. This rash guard is NOT PADDED so if you have a bigger bust or you are modest you might consider a bikini top underneath. Overall, true to color, true to size, made of swimsuit material that holds up well and dries fast.