Warren Buffett turned 87 last week.

By now, it's probably safe to say Berkshire Hathaway's chairman, who's said he has the diet of a 6-year-old and has no interest in getting to work before dawn, has settled on his optimal daily routine.

So what does an average day look like for Buffett, who Forbes estimates is worth $US77.7 billion ($97.1 billion)?

Here's what the Oracle of Omaha gets up to all day:

Buffett wakes up every day at 6.45am

"I have no desire to get to work at four in the morning," he told PBS.

Source: YourStory.com, PBS

At McDonald's...

$US2.61 buys him two sausage patties, $US2.95 snags him a sausage McMuffin with egg and cheese, and a bacon, egg, and cheese biscuit costs $US3.17.

Source: Business Insider, Business Insider

He eats like a six-year-old

The chairman also has a soft spot for strawberry milkshakes. "I checked the actuarial tables, and the lowest death rate is among six-year-olds," Buffett told Fortune. "So I decided to eat like a six-year-old. It's the safest course I can take."

Source: Forbes, Business Insider, Fortune

But he does exercise

Entrepreneur reported that the billionaire still finds time to exercise, in part to counteract his diet.

Source: Entrepreneur, Business Insider

Work begins...

According to CNBC, sometimes the Berkshire Hathaway chairman doesn't roll into work until after the market opens.

Source: CNBC

A big reader

Once he's in the office, he hits the books. CNBC reported that Buffett estimates he spends 80 per cent of his day reading. He recommends that people try to read at least 500 pages a day.

Source: Medium, Business Insider, CNBC

He loves work

The billionaire acknowledged to Fast Company that he doesn't need to keep working. However, he sticks with Berkshire Hathaway because he loves it.

Source: Fast Company

Lunch

When it comes time for lunch, Buffett has been known to take people out for a treat at McDonald's. CNBC reported that he once bought his friend Bill Gates a meal at the fast food giant using coupons.

Source: Business Insider, Yahoo, CNBC

Bridge

Like Gates, Buffett enjoys unwinding after work over a good game of bridge. He gets absorbed in the game: "You know, if I'm playing bridge and a naked woman walks by, I don't ever see her," he told CBS.

Source: Business Insider, Entrepreneur, CBS

Ukelele

He also likes to play the ukulele, a skill he picked up in order to woo his first wife. He once even strummed out a duet with Bon Jovi, for charity.

Source: Entrepreneur, Forbes, NPR, Hear Nebraska

He likes to sleep

When it comes time to grab some shut eye, Buffett likes to be in bed by 10.45pm. "I get quite a bit of sleep. I like to sleep," he told PBS. "So I will usually sleep eight hours a night."

Source: Business Insider, Inc., PBS

This story first appeared in Business Insider. Read it here or follow BusinessInsider Australia on Facebook.