Powerball: Why getting eaten by a shark is more likely than winning the $1.73 billion jackpot

Have you ever wondered what the chances are of being eaten by a shark? Attacked by a grizzly bear? Or being struck by lightning — twice?

What about the odds of winning an Olympic medal? Or becoming president of the United States?

Well, there's a better chance of any of that happening to you than winning Wednesday's Powerball jackpot, now estimated to be $1.73 billion — the second largest in U.S. lottery history.

The odds of winning are 1 in approximately 292 million, which are slightly better than your chances of winning Mega Millions: 1 in about 303 million.

To put those numbers in perspective, the chances of getting eaten by a shark are 1 in 264 million. (The chances of simply being attacked by one are higher: 1 in 5 million.)

The chances of being struck by lightning are about 1 in a million. So you are almost 300 times more likely to be struck by lightning than you are to win Powerball or Mega Millions.

Odds of winning the lottery vs. other unlikely life events

• Winning Mega Millions: 302,575,350 to 1

• Winning Powerball: 292,201,338 to 1

• Being eaten by a shark: 264 million to 1

• Being struck by lightning twice: 19 million to 1

• Becoming U.S. president: 32.6 million to 1

• Dying in a plane crash: 11 million to 1

• Being hit by debris from a plane: 10 million to 1

• Being killed by a bee sting: 6.5 million to 1

• Being attacked by a shark: 5 million to 1

• Being attacked by a grizzly bear: 2.7 million to 1

• Becoming a movie star: 1.5 million to 1

• Being struck by lightning: 960,000 to 1

• Winning an Olympic medal: 662,000 to 1

• Hitting a hole-in-one in golf: 12,500 to 1

• Winning an Oscar: 11,500 to 1

• Bowling a perfect 300 game: 11,500 to 1

• Being injured by a toilet: 10,000 to 1

• Becoming a millionaire: 30 to 1

Sources: Bookies.com; The Motley Fool

Just how unlikely is winning the lottery?

Tim Chartier, a professor of mathematics and computer science at Davidson College in North Carolina, likes to think about it this way: Winning the lottery is the equivalent of flipping heads on a coin 28 times in a row. Twenty-eight times!

Another way to visualize it, Chartier says, is to have someone look back at the past nine years, pick one second and then ask someone else to guess the second they chose. The chances of picking the correct second are about the same as winning the lottery: 1 in 300 million.

Perhaps that’s why he’s never bought a lotto ticket.

“No, I've never played,” Chartier says. “But if it's really meaningful for you to dream about being a billionaire for half a day or a day, as long as you have the ticket, then it's really worth doing, despite how incredibly unlikely it is.”

How the odds of winning are calculated

For Powerball, winners pick five different numbers from 1 to 69 for the white balls and one number between 1 and 26 for the red Powerball. To calculate the odds, there are 11,238,513 possible combinations of choosing five different numbers from 1 to 69. Multiply that by 26, and you get the 292,201,338-to-1 figure.

[Also read: Is winning the lottery all it's cracked up to be?]

For Mega Millions, jackpot winners pick five different numbers from 1 to 70 for the white balls and one number from 1 to 25 for the gold “Mega” ball. To calculate the odds, there are 12,103,024 possible combinations for choosing five different numbers from 1 to 70. Multiply that by 25, and you get the 302,575,350-to-1 figure.

What you can do to improve your odds

There are, however, a few things you can do to improve your chances.

“You do improve your odds when you buy more tickets,” Chartier says. “If you buy 100 tickets, you are 100 times more likely to win. But it's equivalent to me saying you get 100 guesses for that one second that I chose from the past nine years.”

And picking random numbers rather than the ones you always play increases the odds that you don't have to share the jackpot.

“We have a tendency to pick similar numbers, because we often base them on things like birthdays and so forth,” Chartier says. “So picking random numbers really increases the odds that if you win, you won't have to share."