This size notice is for normal body type.
If your weight is more than or less than the measurement given below, please consider ordering one size bigger or one size smaller.
This brand, TheLees, is almost slim fit style.
If you haven't tried slim fit before, you would feel a bit tight so please buy one size bigger.
Tag size given below is the size which is attached on cloth and label.
For example, 5' 11", 165 lbs : If you like slim fit, please choose L sizes{L(US M)}. IF you like normal fit, please choose {XL(US L)}.

M(US S) = 5'7"(170cm), 140 lbs(64kg)
L(US M) = 5'9"(175cm), 155 lbs(70kg)
XL(US L) = 5'11"(180cm), 175 lbs(80kg)
2XL(US XL) = 6'2"(188cm), 190 lbs(86kg)

If you are still unsure about size, Could you please tell us Weight and Height in stones or Lbs and Inch?

[Measurements]
M(US S)... shoulder 43cm, chest 48cm, sleeve 62cm, TTL 68cm
L(US M)... shoulder 44.5cm, chest 50cm, sleeve 64cm, TTL 70cm
XL(US L)... shoulder 45cm, chest 52cm, sleeve 65m, TTL 72cm
2XL(US XL)... shoulder 46cm, chest 54cm, sleeve 66cm, TTL 74cm