How many kanji do Japanese people know?


I am curious how many kanji a normal Japanese person is able to read. Since
the Joyo kanji are learned by middle school, I assume that as a person goes
through high school and university many more beyond the basic 2,000 are picked
up.

For a typical 30-ish year old person in Tokyo with some university degree, how
many kanji would he be able to read?

Furthermore, how often would he have to look up unknown kanji?




The problem with this question is that there are too many variables.

A university degree in a subject like computer science will not significantly
increase a native Japanese speaker's kanji vocabulary. A degree in biology or
medicine will add some, but a degree in philosophy, history, or literature
could potentially add thousands of rarely used (outside of that
specialization) characters.

There's also a huge question about "what does it mean to 'know' a kanji?" Even
very common characters have unexpected readings.

How often a person needs to look up kanji varies depending on what they
generally read. There are some
[lists](https://japanese.stackexchange.com/questions/8098/) of kanji for
particular contexts, but even those are usually too high-level to be of much
'use'. An American who habitually reads "The Economist" is much more likely to
need their dictionary on a regular basis than one who just watches the nightly
news.

(I've marked this as CW to avoid gaining rep for what is essentially an
extended comment complaining about the question, rather than an answer)

