I have a 43 inch chest (5'10" 195) and originally bought a XL as I have found some of Beyonds military level 3 lines to be tight for a large. Turned out the XL was too big and painlessly swapped for a large through their return process. My only complaint is the jacket should have the next size up zippers throughout. Especially the main zipper. The main zipper is just a touch too small and fine toothed resulting in care needed when zipping. It should have the same zipper size all around as the Clutch Field Liner does. If it had those zippers I would 5 out of 5. I also wish it had the same zip open side expenders as the Clutch Field Liner to allow for a layer but that is just a design choice. Picture shows the comparison of thee Clutch zipper vs Lochi. I wear the clutch almost exclusively as a mid layer under a hard shell, wind jacket, or under a uniform top. The Lochi I wear primarily as an outer layer.