The top button is for decoration
The shirt is US size, you could take your usual size
Size Information
0.4 -1 inch errors are allowed due to manual measurement
Size S --- Chest 40.6", Shoulder 17.3", Length 26.4" , Sleeve 7.5"
Size M --- Chest 42.5", Shoulder 18.1", Length 27.2" ,Sleeve 7.9"
Size L --- Chest 44.5", Shoulder 18.9", Length 27.9" ,Sleeve 8.3"
Size XL --- Chest 46.5", Shoulder 19.7", Length 28.7" ,Sleeve 8.7"
Size XXL --- Chest 48.4", Shoulder 20.5", Length 29.5",Sleeve 9.1"
Size 3XL --- Chest 50.4", Shoulder 21.3", Length 30.3",Sleeve 9.4"