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 - Heather Blue1827.5
Adult Medium - Heather Blue19.530
Adult Large - Heather Blue2130.5
Adult XL - Heather Blue2332.5
Adult 2XL - Heather Blue2631