‘Tis the season to start dreaming: Prizes for the Powerball and Mega Millions lotteries have climbed past #300 million, with drawings set for Friday and Saturday.

But don’t quit your day job just yet. The odds of winning one of the jackpots is roughly one in 259 million for Mega Millions and one in 292 million for Powerball. And the chances of winning both, for those of you thinking really big? Roughly one in 75 quadrillion that’s 15 zeros according to data scientists at Allstate.

To understand how unlikely those odds are, it’s worth comparing them to the probability of other unlikely events. Americans are much more likely to get struck by lightning (odds of one in 13,500) or to die in a car accident (one in 645).

While the old lottery campaign “You’ve got to be in it to win it” holds true, the real value in buying a ticket may simply be to enjoy the dream of winning.

Convenience stores make about a dime on a $2 ticket, or about 5 percent to 6 percent on each dollar spent. Winning stores also earn a commission, although the amount varies by state.

Following are the odds of winning the jackpots, as calculated by Allstate, along with the chances of other unlikely events:

• Being a victim of identity theft by the age of 40: 1 in 6
• Getting bitten by a dog while out for a jog: 1 in 133
• Getting a hole in one on your birthday: 1 in 25,000
• Having all of the above happen to one person: 1 in 19,900,000
• Winning Powerball: 1 in 292,201,338
• Winning Mega Millions: 1 in 258,890,850
• Winning both Powerball and Mega Millions: 1 in 75,648,252,765,957,300