The US Powerball jackpot to be drawn this weekend is the largest lotto prize ever offered at an estimated $US1.6 billion ($2.5 billion), breaking the previous world record the game set in 2016, lottery officials say.

No one has won the jackpot since August 3, allowing the prize money to mushroom and generating lots of business at petrol stations and newsstands around the United States, where Americans buy Powerball tickets for $US2 ($3.10) a pop.

To win the big prize, a player must guess all six lucky numbers, including the final “Powerball”.

Players have a 1 in 292.2 million chance of winning the jackpot, and a 1 in 24.9 chance of winning a smaller prize, according to lottery officials.

Winners may elect to receive their money as an annuity, paid in 30 graduated payments over 29 years, or a lump sum cash payment. Both types of winnings are subject to federal and local taxes.

The drawing will occur at 10.50pm on Saturday night (1.50pm AEDT on Sunday) in the Florida state capital of Tallahassee. It will be the 40th Powerball drawing since the August 3 win.

The longest run in the history of the lottery ended on October 4, 2021, when a California ticket holder won a $US699.8 million jackpot after 41 drawings.