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 Blue1827.5
Adult Medium - Royal Blue1929
Adult Large - Royal Blue2229
Adult XL - Royal Blue2331
Adult 2XL - Royal Blue2532.5