So I ordered 1 first in a 2XL and it was a tad loose on me but I kept it anyway becuz I hate making returns. So then I ordered an XL for the 2nd one and that one fits me perfectly!  I am 5'9, 170lbs. I have a 38-40in chest, 15 1/2in biceps, and 30in waist.  I absolutely love this design, seen nothing like it in the states so I definitely recommend this shirt!