> The 2,501 most-used characters have a ranking which expresses the relative frequency of occurrence of a character in modern Japanese. The data is based on an analysis of word frequencies in the Mainichi Shimbun over 4 years by Alexandre Girardi. Note: (a) these frequencies are biased towards words and kanji used in newspaper articles, and (b) the relative frequencies for the last few hundred kanji so graded is quite imprecise.
Jim Breen's KANJIDIC has frequency information.
http://www.edrdg.org/wiki/index.php/KANJIDIC_Project
> The 2,501 most-used characters have a ranking which expresses the relative frequency of occurrence of a character in modern Japanese. The data is based on an analysis of word frequencies in the Mainichi Shimbun over 4 years by Alexandre Girardi. Note: (a) these frequencies are biased towards words and kanji used in newspaper articles, and (b) the relative frequencies for the last few hundred kanji so graded is quite imprecise.