All it takes for any of them is one big hit movie and they are back on top!!

1990s movie stars: Who’s still hot?

Two decades later, how are the biggest movie stars of the 1990s faring at the box office?

Who’s still hot? Who’s not? And the biggest question as far as movie studios and distributors are concerned: which ‘90s stars still have the Wow Factor at the box office?

To most effectively and fairly answer these questions, we did the following. We took 14 of the Top 15 box-office stars of the 1990s (according to the Internet Movie Database, and excluding The Sperminator Governor) and looked at how each’s star-vehicle movies have fared at the box office over the past four years. We ignored their voiceover roles in cash-cow animated or CGI flicks, as well as their ensemble movies, and films in which they had only supporting or bit-part roles. Leading roles only.

We then added their box-office totals from those movies and calculated their averages. But averages alone didn’t seem like a fair way to rank the stars, because it takes only one blockbuster movie to be near the front of the pack (hello, Harrison Ford and Indiana Jones 4). Indeed, some of these actors, such as Ford and Bruce Willis, also have appeared in absolute stinkers that died at the box office, or even went straight to DVD.

So, to punish those actors, and reward those who haven’t had any stinkers, we came up with The Wow Factor (with apologies to Darrell Sheets of TV’s Storage Wars). The Wow Factor is merely the sum of (1) each actor’s average box-office haul and (2) each’s lowest box-office total from 2008 through 2011.

Yes, Sandra Bullock is not only one of the most beloved people in Hollywood, she’s also the most bankable of all the ‘90s stars.

Bullock has appeared in three movies since 2008. Despite one of them being the Razzie Award-winning dog All About Steve ($34 million), the other two were blockbusters — importantly, neither of which was an established franchise (hello, Harrison Ford and Indiana Jones 4). The Blind Side took in $256 million, and The Proposal $164 million. Hollywood must be salivating at her decision to return to acting.

Tom Cruise is the butt of a lot of “has-been” jokes, but the bottom line does not lie. His last three movies have brought in $300 million — and counting, as Mission: Impossible — Ghost Protocol isn’t anywhere near done in theatres. His lowest earner was Knight and Day, at $76 million. That figure dwarfs the minimums of all other ‘90s movie stars in this timeframe.

Adam Sandler’s movies seem to get incrementally worse and less funny, but he is box-office gold. Even his clunky rom-coms bring in at least $52 million. His last five: Jack and Jill ($72 million), Just Go with It ($103 million), Grown Ups ($162 million), Funny People ($52 million) and Bedtime Stories ($110 million).

It is no surprise to see Leonardo DiCaprio at No. 4. His past five movies have averaged $104 million, and that average was sunk by last fall’s moribund J. Edgar ($37 million).

Julia Roberts, the only other female on IMdB’s list of the Top 15 1990s actors, seems to have been quite choosy with her roles since the Grunge Decade, clearly content not to be among the A-Listers anymore.

The lone Canadian, Jim Carrey, would probably rival Adam Sandler’s box-office bang if he’d stop trying to duplicate Robin William’s serious-role Oscar win. To wit: I Love You Phillip Morris ($2 million). While his blockbuster days might now be gone, both Yes Man ($98 million) and even Mr. Popper’s Penguins ($68 million) prove that millions of people still want him to make them laugh.

It isn’t a shock to see Tom Hanks, Kevin Costner, Bruce Willis, Robin Williams and Mel Gibson at the bottom of this list. Each is more hit than miss anymore on the big screen.

Gibson — the surefire No. 1 box-office star of the ‘90s — is now box-office toxicity. His two star turns since ‘08 (and since his publicity-nightmare drunken meltdowns and separations) have earned a combined $44 million, including $0.97 million for The Beaver, a complete disaster.

Maybe he’ll be roaring again by the Twenties.