In my opinion, if you know how many Kanji you know... You don`t know enough.
Obviously, there are going to be exceptions with extremely OCD people who count every single one, remember when they learn a new one and keep track, etc...
But even if you cover all the Joyo in a Japanese class, if you have any real contact with Japanese literature you are going to need to have acquired quite a few more.
I have absolutely no clue how many Kanji I know -though I am totally sure it`s
well over 500. :P With 500 I most certainly wouldn`t be able to read novels. I`d say in an average novel, I pull out the kanji dictionary maybe 5 to 10 times when I don`t know how to read a character. By around the 3rd time I come across the same one I didn`t know I`ve memorized it. Or at least for the meantime. If I don`t encounter it anywhere else for a while, I`m sure I forget it.
If I had to give a guess, I`d say that I can read and recognize around 2000+? But the number fluctuates, the subjects they are related to vary, etc. I know bunches of medical specialty terms, but political and financial stuff I suck at reading.
And I also get to enjoy the amusement of being able to "read" some stuff without having any firm comprehension of it (this is really bad when it comes to the political/financial stuff... Nikkei kills me) because I know what the sound of the word would be but not what it means.
It`s down to interest though, I guess. I don`t usually have all that much interest in the financial/political sections in the newspaper or magazines, so even when I do have interest and put forth the effort to read them and remember the terms... I forget them before the next occasion.
I have found that I am usually about par with native chuu3/kou1 when it comes to speaking and reading... Which I guess I can`t complain about.
Today I had an embarrassing moment when I forgot "疑" while actually reading something aloud and had to stop... Which was really awful.
If the 500 figure ever really comes up, it sounds like it would be closer to the number of Kanji an average technologically savvy adult could write by hand if asked out of nowhere. :P