SHIRT MEASUREMENTS: (measurements are approximate) SMALL: COLLAR TO SEAM: 23.75 inch / 60.3 cm ARMPIT TO ARMPIT: 17 inch / 43.2 cm MEDIUM: COLLAR TO SEAM: 24 inch / 61 cm ARMPIT TO ARMPIT: 18 inch / 45.7 cm LARGE: COLLAR TO SEAM: 24.75 inch / 62.9 cm ARMPIT TO ARMPIT: 20.75 inch / 52.7 cm XL: COLLAR TO SEAM: 25.5 inch / 64.8 cm ARMPIT TO ARMPIT: 23 inch / 58.4 cm