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 - Heather Blue19.531
Adult Large - Heather Blue2129.5
Adult XL - Heather Blue2332
Adult 2XL - Heather Blue2530