One size down if you want it to fit like a regular size t-shirt. Despite this, the sleeves are about 1 inch longer and will need to be adjusted if you want them to fit like a regular t-shirt. Unlike other shirts, they come out of the dryer crumpled. The collar is quite small, but it's not very noticeable on a shirt. All in all not a bad buy, just go down a size and live with the sleeves or adjust them for you.
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