I'm 5'5" and I think maybe 180 lbs. Ordered an X-large since my arms are a bit thicker than most and my ribcage is wider.
This fit just as how I expected. I am going to maybe just cinch it up a bit at the waist maybe so it doesn't look too baggy. But even with out that I would wear it as is, it's not that big of a deal breaker.
The length is perfect for me and the fabric is breathable and light.