I hope this article sheds some light on when to transfer your baby from a baby bath to a big bath.

We transferred our baby from his baby bath to a big (adult sized) bath when he started to hit his head on the top of the baby bath. He would do this by pushing against the end of the bath with his feet and legs. I believe this was when he was around 12 weeks old.

His bathing stages were as follows...

From birth: Baby bath and bath support. We used the bath support for only a little while. I think it was useful initially because he could just lay their looking at us. I have uploaded a photo of Codi in his baby bath with his bath support.

After 3 weeks old: Baby bath and support baby's head with hand. Once I got more confident in bathing, we removed the bath support and I just supported his head with my hand. This really helped me bond with Codi and I am sure he felt more comfortable with my hand rather than the plastic support.

After 12 weeks old: Big Bath and support baby's head with hand. Codi really liked to kick his legs out and this became an issue with the baby bath, he would kick his legs out which would cause him to shoot up the bath and knock the  top of his head. It became clear he had out grown the baby bath.

Now: Not sure when this happened but he now sits in the bath and likes to move around.

Note: I am not 100% certain on the ages stated above. They are only estimates. Codi is now 17 months old now and it is hard to remember that long ago, however I think they are approximately correct. It is more related to how confident you and your baby are though, rather than age based.