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 Heather18.526.5
Adult Medium - Gray Heather19.527.5
Adult Large - Gray Heather2230
Adult XL - Gray Heather2430.5
Adult 2XL - Gray Heather2531