The Mega Millions jackpot has spilled over $400 million and would be the ninth largest winning since the game began in 2002.
With no one hitting the right numbers Friday night, the next drawing on Tuesday is at $418 million.
The top prize has been climbing for more than two months now. Your chance of wining is 1 in about 302 million.
For Tuesday night's Mega Millions drawing, the cash option — which most winners go with — is $263.3 million.
The 24% federal tax withholding would reduce that amount by $63.1 million. However, the top marginal tax rate of 37% means owing a lot more to the IRS at tax time.
Assuming you had no reduction to your taxable income — such as large charitable contributions — another 13%, or $34.2 million, would be due to the IRS. That would be $97.3 million in all going to Uncle Sam.
This means that after federal taxes, you'd be left with $166 million.
Then there are state taxes, which range from zero to more than 8% depending on where the ticket was purchased and where the winner lives.
Nevertheless, the after-tax amount would be life changing. Experts say large lottery winners should assemble a team of experienced professionals — an attorney, a tax advisor and a financial advisor — to help navigate the windfall.
The last time there was a top-prize winner was on March 28, when a Wisconsin man nabbed a $768.4 million jackpot. Manuel Franco, who claimed his haul in late April, chose the lump sum cash option of $477 million. After federal and state tax withholdings, he received $326 million.
CNBC's Sarah O'Brien contributed to this report.