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 - Gray Heather2028.5
Adult Large - Gray Heather21.530
Adult XL - Gray Heather2331.5
Adult 2XL - Gray Heather25.533