Twenty Per Cent

Shalom aleichem Rabbi Lauffer. Thank you for answering my last question. It is brought down in halacha (Orach Chaim 656) that a person is not obligated to spend more than 20% of his money on performing a positive mitzvah. Is the 20% calculated according to his total bank account, or is it calculated like ma’aser kesafim is, according to his yearly income. For example, if a certain mitzvah would cost more than 20% of the man’s income for that year, but it would be less than 20% of his total bank account that he has saved up from forever, would he still be obligated to perform that mitzvah? Thanks a lot.