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 - Brown Heather1826
Adult Medium - Brown Heather19.528.5
Adult Large - Brown Heather21.530.5
Adult XL - Brown Heather2431
Adult 2XL - Brown Heather25.532