[My baby Milo]

My Milo measures 9 around the neck 14 around the widest part of chest and 11 1/2 to his tail. Should I order xs 9-11 neck 14 1/2 -16 1/2 chest and 10 long or should I order small 10 1/2 - 12 neck 15 - 17 chest and 12 long. I know it's sounds crazy but I have bought xs stuff that is to little so my daughter said small but I think it's going to be to big. I haven't bought a lot of clothes for him so in your opinion should i go a little bigger or not.