How Much Really Is Harry Potter's Creator JK Rowling's Net Worth? Find Out Here!

In 2012, Forbes dropped from its ranking the world-renowned Harry Potter series author J. K. Rowling after eight years on its authoritative billionaires list. The magazine blamed high British taxes and large charitable contributions had eroded her fortune.

 "Fantastic Beasts and Where to Find Them," with a script by Ms. Rowling, opened in the United States to a strong $75 million weekend. Even if the first film generates just $500 million in revenue, less than half the highest-grossing Potter films, that adds another $50 million to her fortune, bringing the film total to $700 million.

The two-part drama "Harry Potter and the Cursed Child" is a smash hit in London and is scheduled to open on Broadway next year. Warner Bros. recently licensed the television rights to the Harry Potter films to NBCUniversal for as much as $250 million.

Ms. Rowling is famously private, especially about her financial and business affairs. Not only has she made her fortune largely through her own wits and imagination, but she also pays taxes and gives generously to charity.

Whatever the precise size of her fortune, Ms. Rowling is enormously wealthy, from being a struggling single mother. So where does J.K. Rowling get her wealth from? Here is an estimated calculation by New York Times:

 The seven Harry Potter books have sold an estimated 450 million copies, with estimated total revenue of $7.7 billion. At a standard 15 percent author's royalty, she would have earned $1.15 billion. These books continue to sell strongly years after they were first published.

Ms. Rowling has presumably been able to negotiate better deals for her subsequent books, which include adult mysteries under the pseudonym Robert Galbraith, published by a Little Brown imprint, as well as numerous Potter spinoffs. These works probably contributed at least another $50 million.

Ms. Rowling has been reported that she sold the film rights to the first four Potter films for just $2 million. The first four films grossed close to $3.5 billion and generated an estimated $2.5 billion in profit. If she managed to achieve a 10 percent net profit participation, that's $250 million, according to The Numbers.

The next four Potter films were far more lucrative, generating well over $4 billion in revenue. At 10 percent, that's another $400 million.

Warner negotiated Ms. Rowling's theme park deals on her behalf with the undeniable "Harry Potter" phenomena still rising. She also received a one-time licensing fee estimated at $60 million to $80 million and annual development fees. Like Steven Spielberg from Universal Studios, Rowling also gets a percentage of gross sales of merchandise, food and beverages.

NBCUniversal also bought exclusive television rights to the eight Harry Potter films this summer in a deal valued at as much as $250 million. Ms. Rowling presumably received a large piece of that, at least $125 million. That replaced a deal with Disney estimated to have been worth $50 million or more to her.

Ms. Rowling also has other income. She did not write the play "Harry Potter and the Cursed Child" but no doubt earned a licensing fee and is a profit participant. She earns licensing fees on all Potter-related merchandise. She owns the e-book rights to her books, sold on her proprietary website, Pottermore.

Assuming that she paid Britain's top individual tax rate of 45 percent, she would have been left with $1.2 billion.