Measurements of size 3 Thom Browne shirt. 19 inches from pit to pit. 25 inches from shoulder to the front of the shirt 27 inches from shoulder to the back of the bottom of the shirt.. The shirt is a little bit longer in the back than it is in the front. See pictures. The shirt is in great condition. Size 3 in Thom Browne, which equates to about size large and US sizing please verify sizing with Thom Browne website prior to purchase.