WWW – Hollywood has a bad case of ratings inflation.

Today’s PG-13 movies pack about the same dose of sex, violence and foul language that used to earn films an R rating a decade ago, a new study by Harvard researchers shows.

Using a computerized tally of scenes in 1,269 movies ranked for their raunch, mayhem and profanity, the researchers found that Hollywood got more lenient with its age-based ratings between 1992 and 2003.

“If parents’ expectations about what’s an R-rated movie are based on their own experience from a decade ago, then they really need to get recalibrated,” said Kimberly Thompson, one of two researchers at the Harvard School of Public Health who did the study.

For example, the Motion Picture Association of America gave the 2003 sci-fi action flick “Minority Report,” starring Tom Cruise, a PG-13, broadening its possible audience.

But its content, including scenes of a woman strangled to death and eyeballs in a sandwich bag, would have likely been R-rated in 1992, according to the findings published yesterday in the journal Medscape General Medicine.

Moviegoers said they have long suspected Hollywood is getting lax with its ratings, created in 1968 by the MPAA.

Gordon Blackwell, 65, a consultant from the Bronx, saw the summer blockbuster “Spider-Man 2” yesterday and was surprised by its PG-13 rating.

“It’s very violent and very disruptive, especially for children,” Blackwell said.

“It’s fine to jump over buildings. It’s another thing to crush someone’s skull,” Blackwell said, referring to a scene where the villain, Doc Ock, crushes a surgeon’s head with one of his mechanical arms.

Even a comedy like “Dodgeball” had land mines for parents. “It says PG-13 but it’s not something my son should be seeing,” said Judith Tocaciu, 32, who saw the movie with her 10-year-old son, Sandro.

Tocaciu objected to the movie’s raunchy sexual content. “I didn’t know it was like that,” she said.