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)
Youth Small (6-8) - Tye Dye
Youth Small (6-8) - Tye Dye15.518
Youth Medium (10-12) - Tye Dye17.522.5
Youth Large (14-16) - Tye Dye1822.5
Youth XS (2-4) - Tye Dye13.516