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 - White1727
Adult Medium - White1928
Adult Large - White2129
Adult XL - White2330
Adult 2XL - White2532.5