RE: How long can you use a high chair?
Well, my son is almost 30 months old, and he still sits in high chair :-) One of his friends already sits in a booster chair.
I am not in a hurry to move him out of the high chair, so he can sit in there until he doesn't fit in it anymore :-) He is ~29 lbs and 34.5 inches now.
If you have a younger child then usually they get moved from the high chair when it is about time for the younger one to start using a high chair.
HTH.
Stefani
Mommy to DS born 5 Sep 03