JK Rowling has earned a further NZ$11.2 billion from the Harry Potter brand since completing the young adult book series.
The author who published her last book about the boy wizard in 2007, could see that figure increase to $25.39 billion in the coming years.
The eight novel franchise which concluded with Harry Potter And The Deathly Hallows, includes eight movies, as well as computer games and Potter theme parks at Universal Studios in Hollywood and Orlando.
According to the report the writer, who has sold $210.61 million worth of printed novels in the UK and the US alone, rakes in $1.50 for every Harry Potter book sold, reports British newspaper The Sun.
In addition, her website Pottermore raised $92.81 million in the last three years alone and that sum could stand to rise even further as she is set to release more projects.
Despite coming under fire for her depiction of Native Americans, the author launched a new taster story series called Magic in North America last week as part of the promotion for the forthcoming film adaptation of Potter prequel, Fantastic Beasts and Where to Find Them.
Set for release in November, it stars box office draw and Oscar winner Eddie Redmayne.
Meanwhile, the new stage play Harry Potter And The Cursed Child is also capturing fans imaginations, as it promises to tell a brand new story in two parts. The play, which premieres at London's Palace Theatre this July, has already proved popular, securing $168.39 million of advance ticket sales, according to The Sun.
"With all these new releases on the horizon, the franchise has the potential to become even bigger than during the books' heyday.
"The beauty of the Potter series is that the success of every new part brings back attention - therefore sales - to older parts of the franchise.
"Every successful film will also sell more books, every performance of the play will encourage more people to go to the theme parks, and so on," he explained to The Sun.
JK Rowling's personal fortune is estimated to be more than $791.65 million.