I have always wanted a Levi's jean jacket.  I am a size 8 and I'm 5'10" and ordered this in a Large (I would normally wear a Medium in most clothes). The sleeves were my main concern and they are plenty long.  The jacket is a slim fit and runs a little small. The large is perfect for me. I'll be wearing it with normal tops underneath, and have no intention of wearing sweaters with this.  I don't think sweaters would go well under this.  The color and style of this jacket is exactly what I wanted.