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 Heather1826.5
Adult Medium - Brown Heather19.528
Adult Large - Brown Heather2128
Adult XL - Brown Heather23.530.5
Adult 2XL - Brown Heather24.531