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 - Natural1828
Adult Medium - Natural2029
Adult Large - Natural21.530
Adult XL - Natural2431
Adult 2XL - Natural26.530.5