When they seem ready. Our daughter was about two, went straight into a single bed. If you're worried about a child falling out of bed, you can put a spare mattress on the floor next to the bed until you are confident s/he will stay put :-)

Depends on the child. 2 of ours at 18mo, 2 at 13 months due to a new baby needing it! A matress on the floor can be used if falling out of bed (or being big enough to get in and out) is an issue. Big beds are about consistency with staying in them to sleep- we sat in the room near the door until child feel asleep for the younger ones, the older ones were big enough we could tuck them in and leave.

Then my aunt had one in a crib at 3 yrs- as petite as my kids, 22lbs? Because hey, why have them wander around/wreak havoc if they are happy and safe (cannot climb out) in the crib! ROTFL

My 9 yr old daughter left the crib at 2 and a half because she began to try to climb out, and it wouldn't be long before she succeeded. She took the transition very well. My son is 3 and he's still in the crib. DH and I are thinking about moving him soon, because he's quickly outgrowing it :-).

Around age two - single bed, one side against wall, guard rail on other.

Probably somewhere around 2. Once they started to throw one leg over the side of the rail, we knew it was time to move from crib to bed.

Both just over two into single bed with side rails.

I'm too old to remember, but some days I'd like to get back into mine LOL!

I moved my daughter as soon as she could climb out of the crib -- around two and a half. She liked her new 'big girl' bed.