Andrew G.wrote a review of Fjallraven Raven Jacket - Men's on February 1, 2016
Familiarity: I returned this product before using it
Fit: Runs large
Fjallraven makes great products. The G-1000 material is awesome and super tough. I own two G-1000 shirts which I wear as jackets out in the field. I have taken the G-1000 material through Japanese Barberry, Multiflora Rose, Greenbriar, and rubbed up against countless trees while taking field measurements. They are still in perfect condition. This jacket will be no different as it is the same material.
I don't plan on using it out in the field though. It was pretty expensive but worth the money! I bought this in size medium but ended up returning for a small. I have a 39" chest and an 5'9" weighing in at 150lbs. The medium was actually a really nice fit if I wanted to layer under it. I tried it on with a flannel and a midlayer, which fit very nicely. I just decided to go with a jacket with a little less room. When the small is shipped to me I will probably be able to comfortably wear a flannel underneath or wear a midlayer and have a snug fit.
Comparing this jackets sizing with other products from fjallraven, I would say this is just slightly large.