adidas Kids Size Chart

How to measure: body measurements in inches, over light clothing. Chest/Bust — around the fullest part, tape level. Waist — around the natural waistline. Hip — around the fullest part. Between sizes? Size up.

Size	Age	Height	Chest	Waist
2XS	5–6	44–45.5	24	22
XS	7–8	48.5–50.5	25	23
S	9–10	53.5–55	28	25
M	11–12	58–60	30.5	27
L	13–14	62.5–64.5	34	28.5
XL	15–16	67.5–69.5	36	30

One kids chart for boys and girls; adidas sizes by height and age.

Source: adidas size guide