Reference Size:
M: height=155-160cm weight=41kg-52kg bra size=70A 70B 75A waist: below 26 inch
L: height=160-165cm weight=52kg-60kg bra size=75A 75B 80A waist:26-28inch
XL: height=165-175cm weight=60kg-70kg bra size=80A 80B 85A waist:29-33inch
 
If not sure, can provide your bra size and waist measurement, will help in suggest the size :)