After just a week on release, 'Fifty Shades of Grey' has already passed $100 million box office in the US and $300 million globally. It has claimed the title as the most successful R-rated film opening ever and it's Universal's best-ever opening in 30 territories. The movie is also one of the biggest grossing movies directed by a woman.

Jamie Dornan and Dakota Johnson star in 'Fifty Shades of Grey'
Jamie Dornan and Dakota Johnson star in 'Fifty Shades of Grey'

Ironically for a kinky romance, the film's $85 million opening in America claimed the record for a February release from Mel Gibson's 'The Passion of the Christ'. In the UK, 'Fifty Shades' had the biggest ever debut for an 18-certificate movie and the biggest for a film that isn't a sequel or part of a franchise.

More: Read the review for 'Fifty Shades of Grey' 

"This kind of performance is usually reserved for superhero movies and animation franchises," said's Phil Contrino.

Watch The Trailer For 'Fifty Shades Of Grey' Here:

Despite the box office bonanza, audiences aren't scoring the film very highly, with just a 41% positive rating at IMDb. So it's unlikely that the film will mop up on repeat viewings, which a film needs to do to be a reigning blockbuster. 

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Even so, analysts say 'Fifty Shades' looks certain to continue dominating the box office in its second weekend, fending off competition from the likes of 'Hot Tub Time Machine 2' in America and 'Blackhat' in Britain. And talks have already begun about making the next two books in E.L. James' trilogy into sequels.

More: Fifty Shades Receives New Round of Criticism for Abusive Relationship and "Brand Porn"

At the moment, 'Fifty Shades' is predicted to top out at around $500 million worldwide. Which means it won't quite beat the female-led and directed 'Mamma Mia!' ($609m). But there's another female-led movie that will be harder to beat: in 1972 'Deep Throat' brought in more than $600 million, which would equate to $3.4 billion in today's dollars.