I bought this for my 18 month old in size 2T. He is on the smaller side and this will probably work for this winter/spring and next, with rolling the sleeves this year. It is very thin, which is perfect for wearing layers in Southern California. We love to go to Disneyland when its sprinkling! We also snagged this for a great price...if it was available in the next size up Id probsbly buy that too!