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 1826.50
Adult Medium19.5028.50
Adult Large 21.5030
Adult XL 23.5031
Adult 2XL25.5032.50
Adult 3XL 27.5034
Adult 2XL - Red2532.5