5'10 145lbs big ribcage no muscles 14.5 in neck. My rollneck is so wide it looks ridiculous. the rest of the sweater looks good except its slender. doesn't hang like the picture.I have really skinny arms and it fits snug. neck you can drive a truck through. Recommended size was med. it does stretch. But the neck is wider than my ears. Measured, it was 9 inch laid flat.. "fit guide" not very accurate, so far all my purchases have been tight, I dont like returns.