If you can it is best to measure your little one's head to ensure a great fit for the hats. Use a flexible tape measure and wrap it gently around the head resting above the ears. Repeat a couple times to make sure it's right. If you don't have a flexible tape you can use a string and then lay it flat and measure it.
The following is an approximate size chart and may give you some direction on which size to order:
Newborn up to 14"
3-6 months 14"-16"
6-12 months 16"-18"
1-2 years 18"-19"
2-4 years 19"-20"
I can make other sizes and will try to come close to the exact head size. This is just to give you an idea!
