In the battle of playboy billionaires at the box office, “The Great Gatsby” looks to come in behind “Iron Man 3,” according to estimates. While the new film adaptation of the classic F. Scott Fitzgerald novel is expected to perform well, the latest Marvel blockbuster is riding good word of mouth and the success of last year’s “The Avengers.”

Jay Gatsby might not be throwing one of his lavish parties when the final box-office numbers are announced, if estimates are correct. Box Office Mojo is reporting "Gatsby” tracking to bring in $40 million in its opening weekend. Not a bad haul, but it won’t be able to take down “Iron Man 3.”

Starring Robert Downey Jr. and directed by Shane Black, "Iron Man 3" has received plenty of praise from critics and moviegoers, driving estimates of a $174 million opening weekend. And if Tony Stark's latest escapades see a drop-off similar to “The Avengers,” the movie should be assured a pretty solid second-weekend gross of about $87 million.

“The Great Gatsby” will be helped by a lack of competition. Last week’s box-office runner-up, “Pain and Gain,” will be in its third weekend and last weekend grossed just over $7 million. The other movie opening this weekend, “Peeples,” with Tyler Perry listed as a producer, is not expected to be a big draw; it will be considered a success if it gets to around $15 million. Box Office Mojo is estimating “Peeples” will earn around $14.2 million at the box office.

Despite poor critical reception, the Baz Luhrmann-directed “Gatsby” seems to be doing well with audiences, as Box Office Mojo notes 65 percent of advance tickets for this weekend sold through Fandango have been for “Gatsby.”

“The Great Gatsby” will face some tough competition as “Star Trek Into Darkness” debuts next week, and word of mouth could affect the box office for “Gatsby” after it debuts at the Cannes Film Festival May 15 and on subsequent dates internationally.