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 - White 18.527.5
Adult Medium - White 2028
Adult Large - White 2231
Adult XL - White 23.530.5
Adult 2XL - White 25.530