Lotto NZ is bracing itself for "unprecedented ticket sales" leading up to Saturday's record $50m jackpot.

It's a jackpot that could see those ticket sales make history themselves, with them likely to tip the 2016 record of 2.4 million tickets sold.

Lotto's Marie Winfield said they typically sold about 500,000 tickets for lower jackpot draws.

"But with the jackpot at $42 million last night, sales surged to just over 1.7 million.

"The highest ticket sales for a Powerball draw in history came on 9 July in 2016 when we sold 2.4 million tickets for the $40 million Must Be Won draw.

"We are expecting unprecedented demand for the $50 million Powerball draw on Saturday night, with the number of tickets sold expected to exceed 2 million."

As for why it capped it's jackpot at $50m, Winfield said they were conscious it was a "large sum of money and more people are reaching into their pockets this week to buy tickets".

Powerball was based on a large number of people paying a small amount of money in the hope of winning.

There was also a good chance the Powerball would be split due to the Must Be Won draw.

"In the history of Powerball there have been five times when a Must Be Won Draw with a jackpot of over $30m has been called and on three of those occasions the prize was split."

With Wednesday night's draw, 38 people won second division, with five of those winning Powerball.

"If the same happens on Saturday, the jackpot will be shared by multiple winners."

Winfield added that in the 2018/19 year, Lotto transferred $261.3m to the NZ Lottery Grants Board for the benefit of New Zealand communities.