Lotto's $50m must-be-won jackpot: What are the odds of winning more money?

Lotto's Powerball is now $50 million, but how does it affect your odds of winning now that the jackpot must be struck?

It doesn't at all, according to University of Otago statistician Dr Matthew Parry who said while the odds of winning Powerball haven't changed - 1 in 38 million - the average amount you could now pocket has gone up.

Being a must-win draw slightly complicated the arithmetic because if Powerball isn't struck, it will roll down to the next division.

"The odds of winning Powerball haven't changed but the amount you will win 'on average' has gone up.

"This is because the prize pool has gone up, but also if Powerball isn't struck, there will be more money for prizes in the lower divisions."

As for what your $50m will earn on interest as it sits in your bank account, if the bank gives you a rate of 3 per cent a year, you'll get $1.5m.

After tax it becomes $1,005,000.

The winner doesn't have to pay tax on the prize if they are a New Zealand tax resident.

With this weekend's Must Be Won $50m jackpot, punters now have a chance of winning more money due to the possibility of it spilling to a lower division. Photo / File

The 1 in 38 million odds of winning formula is based on a variety of multiplications of the 7 numbers involved in the draw. It is also based on buying one line of Lotto; so the more lines you buy, the better your odds.

"The only way you can really affect that is by buying more tickets."

As for whether he'll try his luck, Parry said he would be lining up to get a ticket for Saturday's big draw.

Meanwhile, if you did take out the jackpot, it wasn't the time to make any rash decisions, according to Craig Offwood from ANZ's Private Bank team earlier told the Herald.

"From our experience, it's clear what winners do with their prize has a huge impact on the rest of their lives."

Seeking professional advice was an important step in the days after people came into a significant amount of money, Offwood said.

"Many people will inherit money at some point in their life, and although the sum may be less than a Lotto jackpot, the challenge is always the same," he said.

"Over the years, we have seen some great success stories. Equally, there have been some cases where they have squandered their jackpot.

"After failing to heed advice, they have gone on a spending spree with the unfortunate belief the winnings would last forever.

"The last thing you want is to find yourself with no money in 10 years' time."