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 17.5027
Adult Medium 1928
Adult Large 21.5029
Adult XL 23.5031
Adult 2XL 24.5031.50