Width is measured across the chest below the sleeves from seam to seam. Height is measured from the bottom of the shirt to the highest point on the shoulder (where the seam meets the neck).

Please note that each product has its own specific sizing chart.
SizeWidth (inches)Height (inches)
Adult Small - Navy Heather18.527
Adult Medium - Navy Heather1928
Adult Large - Navy Heather2230
Adult XL - Navy Heather22.530.5
Adult 2XL - Navy Heather25.531