Sizes: Chest in inches
S 34/36" M 38/40" L 42/44" XL 46/48" 2XL 50/52" 3XL* 54/56" 4XL* 58/60" 5XL* 62/64"
 
Hannah 50kg 5'5"  Female wears Large
Ian 110kg 6'2" Male wears XXXL
 
Would recommend going up 1 size for comfortable fit