Really depends on the person and the child.  In my dad's case if it's just the two of us I've been responsible for him since I reached double digits and came home from school and made us both lunch because my mum was away and he had nothing lined up.

I think it is more a three phase of responsible for you 0-graduation/first proper job

Life generally apart but with touch points above to 70ish

You for them thereafter and incrementally.

Not cliff edge changes but with blending: eg my mother is in her 7th decade and still a driving force on a couple of charitable boards (including taking responsibility for the staffing and funding of one with grant applications etc).  Yet has been rubbish about practical things for ages: eg she (always quite small and never particularly strong) bought a Volvo in the 90s without power steering and it hurt to drive, so I have been supplying her with vehicles since in my 20s. The being a bit rubbish has come into more and more relief with house needing refurb, bad health decisions (ie pushing them out and not making them), etc.

I agree with all of that  Deemus, there is generally a period when kids are well embarked on a career have their own property etc and parents still in late middle age when there is little active responsibility in either direction,  but interested in the typical tipping point which is probably only discernible in retrospect...

lol at mid 60s

early 50s

really Merkz, why would you need to look after your parents when they are in their early 50s?

My mum is in her late 70s and definitely still feels responsible for us - honestly, I'm not sure that will ever change.  She'll just become more and more frustrated that we're trying to look after her, based on experiences of last few years.

Mine it's really only been the last ten years.  In hindsight moving them in with you speeds up the process as they feel able to then defer lots of things to you.

I think it depends and its variable.

A friend ran businesses worth 100s millions with 1000s of staff and his aged parents felt responsible for him well into his 60s (ie when they hit their late 90s)

I think my parents still worry about me more than i worry about them (late 40s, late 70s) but i think the change is imminent.  

soz guy I wasn’t really paying attention - around 50 is when I had to start doing a lot more for mine, but they were well over 70 at that point 

You have to be a bit unlucky for your parents to need any sort of real looking after until their mid 70s these days surely?  I might take a look if they are signing a contract or be asked for advice if something has a legal angle or they need someone to b*ll*ck the council or something but otherwise not involved. 

Probably for mine when they were in their mid-late 80's, although  now well into their 90's they are still living pretty independently save for me helping out with shopping, hospital visits and finding things...

Donny, they may not take that much physical looking after but at some point there is a subtle shift in who worries most about whom, who compromises for the benefit of the other etc.    I reckon for me that occurred around mid 60s but different for everyone I am sure.

My children look out for me. 5 or 6? 

I have to do more dangerous stuff like cutting crusts off sandwiches but they deal with admin and planning.