It's tagged as 38, but I'd say it does fit half a size smaller, especially in the shoulders. I have a cotton Portland jacket in 38 from 2011, and the size difference is rather big. Just the current tight-fit fashion, I guess.
Unworn, washed once
I'm selling it because I bought it online without trying it on first and it turned out that these particular shades of brown and blue don't look good on me.
Chest - 20.5''
Shoulders - 18''
Sleeve - 25 1/4''
Length - 30''
Gitman Bros. Vintage Navy Gingham Medium
Worn and washed once
Sleeve (top of the shoulder to cuff): 25.5
Back length (from the bottom of the collar): 31