roughly 15-16months old. We needed the cot as the baby was outgrowing the bassinette and trying to roll. She went straight into a big bottom bunk bed. The only issue we have is her waking thru the night and sleeping on the floor usually behind the door... as if she is bored/wanting to escape the room she shares or gets up and plays and crashes on the floor. If we tell her its night night time, she walks off to her room and climbs up onto her bed, so cute! She is very smart!