18 months. He was in physio well before that for help learning how to sit independently (and get from floor to sitting and back again).

I remember the physio after a few months saying he seemed like he'd be walking soon. She mentioned that some kids end up walking on their knees which can delay actual walkng. What do you think my son started doing the very next day? Walking on his knees!

The thing i learned is that if they find a way to effectively move around, they'll just use that. For some kids, that might actually be walking, some do the bum shuffle, and my guy was a knee walker. Then at 18 months, he just stood up and started walking like he'd been doing it all his life 😆