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 Blue18.526.5
Adult Medium - Royal Blue2028.5
Adult Large - Royal Blue2228.5
Adult XL - Royal Blue2430
Adult 2XL - Royal Blue2630.5