I normally wear a medium, but based on the size guide on the product page, I got an x-large. The sleeves are a bit long, but the body of the jacket is HUGE. Like, I could fit at least two of me inside.or sleep inside it. (I've noticed this about other rain coats.not sure why this is a trend.) I also don't like how sticky the interior surface is--it grabs onto whatever you're wearing under it. I do like the full length, the reflective strip on the back, and the venting around the shoulder blades.See full review