Small: (Fits 12-24mo) - Fits up to 18" in chest and 21” in length.

Medium: (Fits 3-4yrs) - Fits up to 20" in chest and 26” in length.

Large: (Fits 5-6yrs) - Fits up to 22" in chest and 31” in length.

X-Large: (Fits7-8yrs) - Fits up to 24" in chest and 35” in length