When laying flat, armpit to armpit measures 20.5 inches.
When laying flat, shoulder seam to the bottom of the arm-sleeve measures 10 inches.
When laying flat, shoulder seam to shoulder seam measures 16.5 inches.
The measurement from the back/middle collar seam to the bottom of the shirt is 26.5 inches.
This shirt is in nice vintage condition and comes from a smoke-free home.
Thanks for looking!