Burger King's national Impossible Whopper rollout is boosting sales and bringing in new customers, according to analysis by Cowen.

Orders including the plant-based burger tend to amount to $10 or higher, compared to Burger King's average check of $7.36 in 2018, according to analyst Andrew Charles.

Traditional beef Whopper sales have also increased since the Impossible Whopper launched.

Jose Cil, the CEO of Burger King parent company Restaurant Brands International, recently told Business Insider that the Impossible Whopper is "something we believe can be a part of the Burger King menu for the long term."

Visit Business Insider's homepage for more stories.

Early signs are pointing to Burger King's national rollout of the Impossible Whopper already paying off for the chain.

In early August, Burger King launched the plant-based burger at more than 7,000 Burger King locations across the US. The rollout followed a four-month test of the Impossible Whopper in certain markets.

Read more: Burger King is taking the Impossible Whopper national and says it's looking into other plant-based 'meat' items

"This is not a gimmick," Jose Cil, the CEO of Burger King parent company Restaurant Brands International, recently told Business Insider. "This is something we believe can be a part of the Burger King menu for the long term."

According to Cil, the Impossible Whopper has attracted a mix of new customers and convinced regular Burger King visitors to try the new menu item. According to channel checks by Cowen, the Impossible Whopper is set to contribute to 6% same-store sales growth in the third quarter at American Burger Kings.

"Our 6% same store sales estimate for 3Q implies instances of one-time consumer trial for Impossible Whopper is sustained, and arguably offset, by awareness that continues to grow with Burger King using TV advertising to promote the innovation," analyst Andrew Charles wrote in a note last Thursday.

Burger King's Impossible Whopper. Antonio Villas-Boas/Business Insider

According to Charles, stores are selling roughly 45 Impossible Whoppers per day. Once national advertising launches, Cowen predicts that figure will ramp up to 50 per store per day. Traditional beef Whopper sales have also increased since the Impossible Whopper launched.

The Impossible Whopper is also apparently convincing customers to pay more. According to Cowen, checks with the plant-based burger tend to be $10 or more, compared to the average Burger King order of $7.36 in 2018.

"While data is limited, our check suggests Impossible Whopper is attracting new and lapsed users to the brand that skew younger and affluent, as well as driving high rates of repeat orders," Charles writes.

With the apparent success of the Impossible Whopper, other chains have been quick to test their own plant-based menu items. Impossible Foods' rival Beyond Meat has recently announced partnerships with KFC, Subway, Dunkin', and Del Taco.