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 - Denim Blue1827.5
Adult Medium - Denim Blue19.528.5
Adult Large - Denim Blue21.529
Adult XL - Denim Blue2331
Adult 2XL - Denim Blue2531