Upper Size Guide:
S: Chest 36 inches
M: Chest 38 inches
L: Chest 40 inches
XL: Chest 42 inches
XXL: Chest 44 inches

Trouser Size Guide:
S: Waist 30 inches
M: Waist 32 inches
L: Waist 34 inches
XL: Waist 36 inches
XXL: Waist 38 inches