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 - Royal Blue16.526.5
Adult Medium - Royal Blue19.528
Adult Large - Royal Blue20.530
Adult XL - Royal Blue2330