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 - Royal Blue12.516.5
Toddler 3T - Royal Blue1318
Toddler 4T - Royal Blue1518.5