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)
Toddler 2T - Gray Heather1014
Toddler 3T - Gray Heather11.514
Toddler 4T - Gray Heather1215.5