Sandra Bullock doesn't know how long her break from acting will last.

The 57-year-old actress admitted she is "so burnt out and tired" that she needs to take a hiatus from filming but is unsure of when she will return.

She told The Hollywood Reporter: "I don’t want to be beholden to anyone’s schedule other than my own. I’m so burnt out. I’m so tired, and I’m so not capable of making healthy, smart decisions and I know it."

When asked how long the break will last, she replied: "I really don’t know."

Sandra admitted that she has relied on work as a "crutch" and needs to take a step back.

She explained: "Work has always been steady for me, and I’ve been so lucky. I saw it possibly was becoming my crutch. It was like opening up a fridge all the time and looking for something that was never in the fridge. I said to myself, ‘Stop looking for it here because it doesn’t exist here. You already have it; establish it, find it and be OK not having work to validate you.’"

And Sandra says producing 'The Lost City' with Liza Chasin was a great way to "go out with a bang".

She said: "I love working with artists, and that’s why Liza and I were very well-matched. If I’m going out with a bang, I want to go out with the right person."