When Can You Retire?
What assumptions do you make about social security, cost of living?
More generally, how do you also calculate this age?
A dramatic part of the answer may involve answering the question "WHERE can you retire". If you are willing or interested in retiring in another country, there seem to be several lovely choices where you can have a good life at a fraction of the cost of retiring in the USA.
When your reliable passive income exceeds your cost of living you can probably retire.
Aside from that, the issue is too complicated and important to not seek professional guidance.
When you can live off of 4% of your investment assets.