At just 14 years of age, Stranger Things actress Millie Bobby Brown will reportedly earn up to $390,960 ($US300,000) per episode for her role as telekinetic orphan Eleven in the popular Netflix sci-fi series.

According to Deadline, Brown and her co-stars Finn Wolfhard, 15, Gaten Matarazzo, 15, Noah Schnapp, 13, and Caleb McLaughlin, 16, all negotiated massive pay rises for the show’s third season, jumping from five-figure to six-figure episode fees.

But Brown earned the biggest pay rise according to Deadline, boosting her per-episode pay from $39,048 ($US30,000) in season two to as much as $390,960 ($US300,000) for season three.

This places her closer to the earnings of the show’s two major adult stars, Winona Ryder and David Harbour, who will receive up to $455,500 ($US350,000) an episode.

When you consider season three consists of nine episodes, that puts her possible season salary at around $3.5 million ($US2.7 million).

Wolfhard, Matarazzo, Schnapp and McLaughlin have reportedly secured just shy of $325,387 ($US250,000) an episode.

Less regular stars like Natalia Dyer and Charlie Heaton will reportedly earn between $130,000 to $195,000 ($US100,000-150,000) an episode.

Brown, who appeared in the first season of the show when she was 12, was the undisputed breakout star of the series, earning both an Emmy and SAG Award nomination for her performance.

In 2016 industry website the Internet Movie Database (IMDb) named Brown its breakout star of the year based on the number of page views her profile received.

The third season of Stranger Things will go into production this month, but won’t appear on the streaming service until 2019.

https://twitter.com/milliebbrown/status/980163743827902464

The show’s creators, brothers Matt and Ross Duffer, made an early commitment to continue using their young stars despite the challenge posed by their rapidly changing appearances.

“Even if we didn’t want to deal with [puberty], we have to deal with it because our real-life actors are going through it. I think that’s exciting because it forces the show to evolve and become something different every year,” they told Entertainment Weekly last year.

Meanwhile, Brown’s next project outside the show is to produce and star in a series of films based on the Enola Holmes Mysteries books, which tell the story of Sherlock Holmes’ younger sister, who shares her famous brother’s talent for solving crimes.

Speaking to The Daily Mail, Brown’s Stranger Things co-star Harbour, 42, said he held concerns for her wellbeing considering her fame at such a young age.

“She is in the cross-hairs of something extremely dangerous that nobody seems to be paying attention to,” he said of Brown, who has 15.6 million Instagram followers.

“I think the developing mind of someone who gets this famous and has still a brain that is not fully developed is an extremely difficult thing to navigate, and I hope that she gets the help that she needs.

“I know she has tremendous potential and my hope is that she can remain grounded and protected as much as possible.”