I usually wear XS and ordered this S, it fits perfectly so it does run a bit small. The style and fit are really nice, it looks good on the body. The fabric however is VERY thin, so an underneath shirt is mandatory. This makes this shirt less appropriate for formal settings, which is why I had bought it in the first place. Not sure I'll wear it for what I had intended, although I will keep it because it's worth the dollar. In my opinion this shirt would be much superior if the fabric was thicker. Another thing that can't really be seen in the picture is that the fabric on the sides and pockets is different, thicker than the rest of the shirt, so it is not a uniform fabric throughout. Which I think it's another unfavorable characteristic, that's why it's getting 4 stars.