J.K. Rowling is no doubt one of the publishing world’s most consistent money makers—if not its best ever—and she is notoriously private, especially when it comes to her vast fortune. That means her net worth is a close-kept secret and the subject of rampant speculation.

Given the success of her new film Fantastic Beasts and Where to Find Them, there’s a new estimate of her worth, courtesy of New York Times writer James B. Stewart, who pegs it at at least $1.2 billion.

Fantastic Beasts grossed some $75 million on its opening weekend in the United States alone. It garnered another $150 million at the international box office. The movie’s success—along with the hugely popular Wizarding World of Harry Potter parks, the hit play Harry Potter and the Cursed Child in London, and a television licensing deal for the Harry Potter movies—means the author’s fortune has likely skyrocketed of late. In his calculation, Stewart took into account those factors and others, including the genesis of Rowling’s staggering wealth—the Harry Potter books.

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  • The 450 million copies of the seven Harry Potter books that have sold so far have generated an estimated revenue of $7.7 billion. If Rowling took a standard 15% author’s cut of that, she would have earned $1.15 billion from the novels.
  • Her subsequent, non-Potter books likely earned her another $50 million.
  • The first four Harry Potter films grossed nearly $3.5 billion, with a profit of $2.5 billion. A 10% net profit participation cut for Rowling would mean she took in $250 million from those movies.
  • She could have earned another $400 million from the next four Harry Potter films, which generated more than $4 billion combined.
  • If Fantastic Beasts ends up grossing $500 million—a low-ball estimate at this point—Rowling could see another payday of $50 million, bringing her film fortune alone to $700 million.
  • Rowling earned a one-time licensing fee of between $60 million and $80 million for the Wizarding World theme park attractions, plus she earns a share of ticket, merchandise, food, and beverage sales. Altogether, Stewart estimates she’s taken in roughly $100 million from the parks.
  • Finally, the licensing deal in August that gave NBCUniversal the exclusive TV rights to the eight Harry Potter movies likely added another $125 million to Rowling’s fortune.

In total, Stewart estimates that Rowling’s earnings from books, movies, theme parks, and television total about $2.2 billion. If she paid Britain’s top tax rate for individuals of 45%, she’d end up with $1.2 billion. And that figure doesn’t count the licensing fee she likely earned from the Harry Potter play, licensing fees from Harry Potter merchandise, investment income, and capital gains.

When Fortune asked for confirmation of the Times‘ estimate, a representative for Rowling declined to comment. Rowling’s website touts her privacy, noting that she rarely does interviews or public speaking events. But the author is rather active on Twitter and was especially vocal during the U.S. election. She repeatedly leveled sharp criticism at President-elect Donald Trump, at one point calling him “a giant orange Twitter egg.”

Rowling is also known for her philanthropy. In 2012 Forbes knocked the author off of its billionaire list, in part, because she gave away an estimated $160 million.

Her penchant for charity is one reason why Stewart undertook the net worth estimate in the first place. As a publishing icon—enriched by her own brains and literary brawn—who also pays taxes and gives generously, he argues that Rowling is a rarity among today’s business moguls and celebrities and a role model to many.

This story has been updated to reflect a response from Rowling’s representative.