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
Adult Medium 2028.50
Adult Large20.5030
Adult XL 2331.50
Adult 2XL 25.5033
Adult 3XL 27.5033.50