From Roxy Jacenko to Oprah Winfrey: 12 celebrities share how much sleep they get each night.

There’s simply no better feeling than hitting the pillow after a long day of work. But the promise of a restful nights’ sleep quickly shatters when it comes time to set the alarm.

You start to realise exactly how little sleep you’ll get, so you begin to bargain with yourself. How much time do I really need to get ready in the morning? Surely I can leave a little later for work and still get to the office at a reasonable time?

Choosing between more sleep and becoming stuck in a morning rush is something many of us struggle with.

And we’re constantly being told we need at least eight hours of sleep to maintain a healthy lifestyle, but unfortunately, that’s a luxury not many of us have time for.

To find out how much sleep we really need to function, we decided to take a look at how much shut-eye successful people get each night.

After all, they’re the ones who have to run a business or a country – surely they have this whole sleep thing figured out.

Roxy Jacenko

The successful businesswoman, influencer and mum-of-two survives on just four hours of sleep.

“I don’t really sleep that much. I get four hours… I’m probably a miserable b*tch but that’s just how it is,” Jacenko told Kyle and Jackie O.

Jennifer Lopez

The actress, singer and businesswoman swears by a full eight hours of sleep.

"Sleep is my weapon," she told OK! Magazine.

"I try to get eight hours a night. I think what works best is sleep, water and a good cleanser."

Bill Gates

The Microsoft billionaire gets a reasonable seven hours of sleep a night.

"Even though it's fun to stay up all night, if I have to be creative I need seven hours.

"I can give a speech without much sleep, I can do parts of my job that way, but in thinking creatively, I'm not much good without seven hours," Gates told The Seattle Times.

Elon Musk

Tesla CEO, Elon Musk routinely wakes up at 7am after just six hours of shut-eye.

“I actually measured this with my phone,” Musk wrote in a Reddit AMA in 2015.

“Almost exactly six hours on average.”

Martha Stewart

The businesswoman and lifestyle guru gets by on a measly four hours of sleep per night.

“It’s an exhausting lifestyle, and I always say sleep can go. It’s not important to me right now,” she told Web MD.

“I never stay in bed late - I can’t! In my house, the first people arrive at about 6:30am, and I have to be up well before that.”

Kevin Rudd

According to Kevin Rudd's wife, Therese Rein, the former Prime Minister could get by on just three hours of sleep. And he was like that even at university.

"He doesn't need a lot of sleep," says Rein. 

Dalai Lama

The Dalai Lama believes sleep is necessary for a calm mind and strives for at least eight hours every night.

"For me, sleep, sound sleep usually eight hours, sometimes, last night, nine hours," he said in a 2012 interview with the Huffington Post. 

Julie Bishop

Former Foreign Affairs Minister, Julie Bishop would try for at least six hours of sleep.

“I try to get at least six or seven hours sleep per night, although that can be challenging when travelling through different time zones,” she told Body and Soul. 

Mariah Carey

Mariah Carey told Interview magazine in 2007, "I've got to sleep 15 hours to sing the way I want to."

"Literally, I'll have 20 humidifiers around my bed," she also told V magazine.

"Basically, it's like sleeping in a steam room."

Oprah Winfrey

The American talk-show host, actress and billionaire says she usually gets to bed by 10pm for a full eight hours of sleep.

“The last thing I do before I go to sleep is write five things that gave me great pleasure or that I was grateful for,” Winfrey told the Hollywood Reporter. 

Barack Obama

The former U.S. President is known to stay up past midnight and run on as little as four or five hours of sleep.

Obama shared on Live With Kelly and Michael in 2014 that he stays up “until like two o’clock at night, reading briefings and doing work” before waking up “at a pretty reasonable hour, usually around 7.”

Ellen DeGeneres

The comedian and television host makes sure to get around eight hours of sleep a night.

“I’m usually asleep by 11 p.m. and up around 7:30 a.m. It’s a lot!" she told People. 

Which sleep routine surprised you the most? Let us know in the comments below.