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 - Gray Heather17.527
Adult Medium - Gray Heather19.528
Adult Large - Gray Heather2228.5
Adult XL - Gray Heather2430
Adult 2XL - Gray Heather25.531.5