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 Medium - Green Heather2127
Adult Large - Green Heather2327
Adult XL - Green Heather2530
Adult 2XL - Green Heather27.530