Size chart: S -> 5.25 ~ 5.5 ft & 110 ~121 lbs M -> 5.5 ~ 5.74 ft & 121 ~143 lbs L -> 5.74 ~ 5.9 ft & 143 ~165 lbs XL -> 5.9 ~ 6.07 ft & 165 ~176 lbs XXL -> 6.07 ~ 6.17 ft & 176 ~187 lbs XXXL -> 6.17 ~ 6.3 ft & 187 ~198 lbs Size Specifications: (Chest Circumference) Small: 34 to 36 inches Medium: 36 to 38 inches Large: 38 to 40 inches X Large: 40 to 42 inches XX Large: 42 to 44 inches XXX Large: 44 to 46 inches