I think it depends on the baby, but DS could hold his head up for a second or two a couple of days after birth. Now he can pretty much hold it up indefinitely.
DD has been able to hold her head up briefly since birth.
I'd say around 2 months or so I stopped having to hold her head when I was carrying her up on my shoulder (because if she got tired, she could just rest her head on my shoulder). Now, at almost 3 months, I rarely need to support her head for her, although I still will usually lean her against me when I have her sitting up. She can go in the Bumbo, though.
Most babies can hold their head up at birth ...it's control that is the issue. All babies develop head control at different paces, but between 2-4 months, they should be able to hold it up with control fairly well.
Re: How old when babies can hold their head up?
DD has been able to hold her head up briefly since birth.
I'd say around 2 months or so I stopped having to hold her head when I was carrying her up on my shoulder (because if she got tired, she could just rest her head on my shoulder). Now, at almost 3 months, I rarely need to support her head for her, although I still will usually lean her against me when I have her sitting up. She can go in the Bumbo, though.