According to Brown's contract obtained by The Blast, the 13-year-old actress agreed to be paid $1,000,000, plus a cut of the back end, to star as Maddie in "Godzilla: King of Monsters."
The million bucks is great ... but if she comes back for a sequel she'll make $3 million ... and if the first one grosses over $750 million worldwide, that number gets bumped up to $4.5 million.
The movie started filming in June, and producers wanted to make sure her schedule would be clear of any commitments related to her hit Netflix show.
Along with the fat paycheck, Brown gets up to a 5% cut of all the merchandising around her character ... and Godzilla toys are big sellers.
"Godzilla" producers had to agree not to use her likeness to sell weapons, alcohol, tobacco products, prescription drugs, personal hygiene products, or sexually orientated products ... as well as not do anything that would conflict with her existing Calvin Klein and Converse campaigns.
Brown is already flexing her big Hollywood muscles, because the contract states her name must be displayed in the main titles and on its own separate card.
The film also stars Vera Farmiga and Kyle Chandler ... it's set to premiere in 2019.
BTW ... Brown's "Stranger Things" character, Eleven, would be happy to know a million dollars can buy 420,178 boxes of Eggos -- ya, we did the math.