UK Powerball's £300M jackpot looks smaller than the US's $567M, but it's not the exchange rate. The UK figure is after tax—and the US number never has been.

Powerball ticket sales in the United Kingdom will begin Tuesday, allowing players there to compete for the same massive jackpots as U.S. players

Powerball will see UK players pay £4 per line to compete with their US counterparts to win shared jackpots that can balloon into the billions, paid out over 30 years.