Yoke measurements have changed on stock size shirts in the 25 years I have been in business. When I first started. a 15 1/2 size shirt had a 18 1/2 yoke. As men started to work out more, suit jackets became fuller as did yoke measurements.n Standard became 19 1/2. The style for oversized became very popular. I remember making shirts with a 21" yoke on Medium sized shirts. The yoke measurement is down to about 19" on a 15 1/2 shirt.