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 (5-6) - Black1620
Youth Small (5-6) - Oxford Grey1620
Youth Medium (7-8) - Black1823.5
Youth Medium (7-8) - Oxford Grey1823.5
Youth Large (10-12) - Black18.524
Youth Large (10-12) - Oxford Grey18.524
Youth Large (10-12) - Silver18.524
Youth XL (14-16) - Black1925.5
Youth XL (14-16) - Oxford Grey1927
Youth XL (14-16) - Silver19.525.5