Go with a medium. Small will be too small. But keep in mind different fabrics fit differently. For example the chambray's fit slightly looser, while the over dyed oxfords fit slightly smaller than the regular oxfords even. For comparison I'm 5'10 135 but a small fits me fine depending on the fabric. I feel the over dyed oxfords fit a tad too small for me, so I'm pretty much out of luck for those as medium is going to be huge.