Sizing: Small is for someone that is around 130 lbs, 5'7", chest = 32" and waist = 27". Medium is for someone that is around 155 lbs, 5'10", chest = 36.5" and waist = 32". Large is for someone that is around 185 lbs, 6'0", chest = 40" and waist = 32". XL is for someone that is around 220 lbs, 6'3", chest = 44" and waist = 36".