(M) Measurements from Armpit to Armpit are: 21 Inches.
Measurement from Back of Shirt: 26 Inches.
(L) Measurements from Armpit to Armpit are: 23 Inches. Measurement from Back of Shirt: 27 Inches.
(XL) Measurements from Armpit to Armpit are: 24 Inches.
Measurement from Back of Shirt: 27 Inches.
(2XL) Measurements from Armpit to Armpit are: 26 1/2 Inches.
Measurement from Back of Shirt: 27 Inches.