It's official; Guy Ritchie's 'King Arthur: Legend of the Sword' led by Charlie Hunnam is one of the biggest movie flops of the year to-date. Reports suggest that the film will now gross just $18 million in the US following its first three days; a huge fail when the film's production budget is around the $175 million mark.

Charlie Hunnam leads the cast in Guy Ritchie's 'King Arthur: Legend of the Sword'Charlie Hunnam leads the cast in Guy Ritchie's 'King Arthur: Legend of the Sword'

This means that if 'King Arthur' is to make its money back - including marketing costs not factored into the production budget - it will have to make around $350 million more across the world. In short, Warner Bros are looking likely to have egg on their face when all is said and done with this flick.

The news comes as somewhat of a surprise, as advanced screenings saw a positive buzz generate on social media, with high attendance numbers at those viewings. The promotional support for the film has also been heavy, with hype surrounding it seemingly at an all-time high. Unfortunately, that's not translated to bums actually being on cinema seats in the US at least, so WB will be looking for big moves to be made abroad if they're to make any semblance of respectable money back.

Things aren't looking good however, with other massive films out now and later into the month such as 'Alien: Covenant' and the new 'Pirates of the Caribbean' release, burying 'King Arthur' as they smash through and soak up those who want to go out and hit the movies.

Moving into summer, it's going to be interesting to see if 'King Arthur' is the start of a bad thing for big money releases later this year. Analysts have already released their reports claiming that the US box office total between May and Labor Day (September 4) will be the lowest it's been for a decade.

Whatever the case may be, those working on big flicks will have to do something special if they're to make their mark this year. The movie business could be about to get very messy.

More: Charlie Hunnam Trained Like A Professional Athlete For 'King Arthur'

'King Arthur: Legend of the Sword' is available in movie theatres now.