Sleeve length for a medium is 34".
Sorry this took awhile. I am 5'10" and ordered the large. Sleeve length is just right. Wouldn't want it any shorter. Also this shirt runs small. Like I said I am 5'10" medium build - and am borderline on needing the x-large. The arms themselves are snug on me in the large. I love-love the shirt. Very cozy. Also gifted one to my 78yr old mother and she really likes it too.