SHIRT MEASUREMENTS: (measurements are approximate) MEDIUM: COLLAR TO SEAM: 23 inch / 58.4 cm ARMPIT TO ARMPIT: 21 inch / 53.3 cm LARGE: COLLAR TO SEAM: 25.25 inch / 64.1 cm ARMPIT TO ARMPIT: 21.25 inch / 54 cm XL: COLLAR TO SEAM: 25.5 inch / 64.8 cm ARMPIT TO ARMPIT: 22.5 inch / 57.2 cm