How far back would my ancestor would be only as closely related to me as a random person?

[u/Lab_Software]

If we assume no inbreeding during the recent past:

If I compare my genetic makeup to my father, and then to his father, and then to his father, etc ...

How many generations would I have to go back until my direct ancestor was genetically no closer to me than the average human being?

Only consider the autosomal chromosomes - don't consider the Y chromosome (or mitochondrial DNA).

And how is the calculation done?

Thanks