We have a 6 month old little boy. His baby mattress has a side that's firm (for infants) and a side that is soft (for toddlers.) He's about 19 lbs (last time weighed) and I am wondering when should I flip his mattress over.
But more generally, for future reference, when does child stop being an infant and becomes a toddler?
The reason why I asked this is that I want to know the transition period from when a child stops being an infant and becomes a toddler. I figured that a toddler stops being a toddler around 3 - 4 years and my kid is nowhere near there.
Generally speaking, a child becomes a toddler at around 1 year. This is around the time when they start walking.
About the mattress, keep it on the firm side as long as it isn't impacting their sleep. If you do think it is impacting sleep you might still want to wait to turn it over. The firmer side helps prevent SIDS by keeping it easy both for babies that roll over on their stomach to keep their breathing clear and also for them to roll back over.