https://slate.com/technology/2018/10/mega-millions-lottery-jackpot-ticket-odds.html
As we wrote when the jackpot was a mere $970 million last week, you can do the math by multiplying the size of the winnings (very large) by the probability of you winning (very low) to get the value of your ticket. For this new $1.6 billion jackpot, ignoring tax implications, the value of a ticket comes out to be $5.53—a very good deal.