AJ-JpnRa Tool
「AJ-JpnRa Tool」 is Japanese text readability analysis program.
...If you combine essential Chinese character of Elementary and Middle school, you can have the regular-use Chinese characters.
And the AJ-JpnRa Tool has the Chinese character database of JLPT also, which was built by using the questions from previous JLPT and New JLPT tests last 23 years.