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 16.7526.50
Adult Medium19.5027.50
Adult Large 21.5029.50
Adult XL 22.5029
Adult 2XL2531
Adult 3XL27.5033