He said an Oscar nomination was good news for The Darkest Hour, which follows Winston Churchill and his appoinment as prime minister during the early days of World War II.
"It keeps it in the public conversation for a lot longer," he said. "You have a long tail on the release of your film, it stays in theatres a lot longer, it stays in the news."
He estimated box office takings would increase around 20 per cent because of its Oscar nominations, which also include Gary Oldman up for best actor, cinematography, make-up, costume and production design.
McCarten is one of several Kiwis nominated in today's awards ceremony, with Maori singer Keala Settle nominated for best original song for This Is Me from the Greatest Showman.
Weta Digital are also nominated for their work on War For the Planet of the Apes and Guardians of the Galaxy Vol. 2.
Today's Academy Awards kick off at 2pm.