12M (9-12 mo) 18M (12-18 mo) 24M (18-24 mo)

S (Age 8-10) M (Age 10-12) L (Age 12-13) XL (Age 13-15)

2T (Age 1-2) 3T (Age 2-3) 4T (Age 3-4)

XS: chest 31.5-35in S: chest 35-37.5in M: chest 37.5-41in L: chest 41-44in XL: chest 44-48.5in XXL: chest 48.5-53.5in 3XL: chest 53.5-58in 4XL: chest 58-63in 5XL: chest 63-68in