Note: the following dimensions show the size of the shirt. You could measure your similar shirt then compare to this size chart to choose the best fit size.
Size Chart(Unit:inch)
US S = Tag M(Shoulder: 16.53 Inch; Chest:36.66 Inch; Sleeve: 23.01 Inch; Length: 26.52 Inch; )
US M = Tag L(Shoulder: 17.00 Inch; Chest:38.22 Inch; Sleeve: 23.4 Inch; Length: 27.3 Inch; )
US M+ = Tag XL(Shoulder: 17.47 Inch; Chest:39.78 Inch; Sleeve: 23.79 Inch; Length: 28.08 Inch; )
US L = Tag 2XL(Shoulder: 17.94 Inch; Chest:41.34 Inch; Sleeve: 24.18 Inch; Length: 28.86 Inch; )
US L+ = Tag 3XL(Shoulder: 18.41 Inch; Chest:42.9 Inch; Sleeve: 24.57 Inch; Length: 29.25 Inch; )
US L++ = Tag 4XL(Shoulder: 18.88 Inch; Chest:44.46 Inch; Sleeve: 24.96 Inch; Length: 29.64 Inch; )
US XL = Tag 5XL(Shoulder: 19.11 Inch; Chest:44.46 Inch; Sleeve: 9.75 Inch; Length: 30.42 Inch; )

• Machine Wash Cold, No Tumble Dry; Hand Wash, Hang to Dry
• Slim fit, fits true to size, good quality Fabric, and making style make you feel good and comfortable when wearing
• Button-down collar
• Our Shirts are Slim Fit. So If You want to loose fit, You Had Better Order One Step Bigger Size than Your Original Size. And You can mix and match These Button Down Shirts with so many Formal Trousers and Stylish Denim Pants for the Daily and Office look.
• Great for dailywear and also as neat uniform.

Machine Wash Cold, No Tumble Dry; Hand Wash, Hang to Dry