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 Heather1828.5
Adult Medium - Gray Heather2028.5
Adult Large - Gray Heather21.531.5
Adult XL - Gray Heather23.532
Adult 2XL - Gray Heather24.533.5
Adult 3XL - Gray Heather2631.5