A common refrain in online babywearing groups lately is, "get a toddler carrier, it'll last longer." Now, if someone has a 2yr old and is considering purchasing their first carrier to only use with the 2+yr old child, that is pretty good advice. However, I regularly hear it referencing children under a year. Many have tried to explain why a too big carrier is a bad idea including questions of comfort for the parent and child. But I wanted a quick reference for what happens when baby has to overextend. I borrowed my almost 5yr old (because she's compliant and follows directions), and took a couple pictures.
When her legs are bent, she can open them about 12inches from the inside of one knee to the other. (I used the seam on the jeans as my consistent measure point).
This is open "as wide as you can, and with legs hanging off the edge of support... similar to a carrier that isn't quite knee to knee.
Now, I then had her sit on the floor, straight legs, and do the same thing. She makes about 11inches. She loses a full inch of flexibility by not being able to bend her legs.
Meanwhile, we can look at the child in a carrier that is "too small."
So, the answer to the question, "to size up" has more to do with what your child needs. Is an infant/standard size carrier no longer working for your child? Why? Is it just because she isn't perfectly knee to knee? That is not a reason to size up. There is a full 2in or more gap between fitting a standard carrier "perfectly knee to knee" and fitting the next size up carrier at all. Most families will never NEED a toddler carrier. They may WANT one. There is nothing wrong with that. But sizing up too early doesn't help you or your baby to have a comfortable babywearing experience.
Posted by Ann Marie