• Size 1 is for chest measurements of 19 3/4 - 21 1/4"
    Answered on 1/20/2016 3:05:11 PM by Product Specialist Greg from Sierra Trading Post
  • Size 1 is 1T. My daughter has been living in these size 1 shirts all winter from age 4+ months (we just rolled up the sleeves) -- we highly recommend them!
    Answered on 4/3/2016 1:36:03 PM by BB from NY