Having owned a one of these vests forever I thought it time to get a new one. The size tag on the original was gone but based on the described sizes I ordered an extra small. Disappointed! I have a measured 38" chest (my wife sews for a living) and this vest, at the arm openings, looks like it was designed for someone with shoulders belonging to some one much larger... oh well. I'm an older feller so I will wear it and get used to it,,,