The city has identified 67 career criminals who are getting sentenced so often for so many low-level offenses that they’re effectively “serving a life sentence 30 and 60 days at a time,” a top mayoral aide said yesterday.

John Feinblatt, the mayor’s criminal-justice coordinator, said the rap sheets of the 67 have been red-flagged in hopes that judges will prescribe stiffer sentences when the recidivists inevitably turn up again in their courtrooms.

They were selected from a larger group of 693 with at least 10 convictions in the past two years.

Mayor Bloomberg promised in January during his State of the City speech that his administration would compile a “dirty dozen” list of the worst misdemeanor offenders in each borough in an effort to keep the worst criminals off the streets for as long as possible.

In turned out that 60 wasn’t enough, and the list was expanded to 67, each with an average of 16.6 convictions on their records over two years.

That’s once every 44 days.