The shortfall between how much Kiwi pensioners are spending and what they get from the state is increasing, putting more pressure on people to find the money elsewhere.
Massey University's Westpac Fin-Ed Centre has updated its annual Retirement Expenditure Guidelines and it shows transport and health costs have pushed up the cost of living for retirees.
They show a single person living in a major city like Auckland, Wellington or Christchurch on average spent $590.44 a week for the year to June 30, 2017 to live a "no frills" life.
That was $200 more than the $390.20 after tax rate that an over 65-year-old received in New Zealand Superannuation.
While a couple living a "no frills" life in a major city spent $872.22 a week - $272 more than the $600.30 paid by to them by the Government after tax.
The shortfall for those living in provincial areas was lower - but not by much.
Singles living in a provincial area spent $561.04 on a no frills budget - nearly $171 over what they were paid by the Government, while couples in provincial areas spent on average $621.48.
The research found that there was no group - either those living single, or as a couple, or those living in the town or the city - which lived off New Zealand Super on its own.
That was a change from the 2016 data when the research showed a couple living a no frills existence could live off NZ Super and have $65 spare a week.
While singles living provincially had a shortfall of $36.23 in 2016.
Claire Matthews, author of the research and director of academic programmes at Massey University, said the shortfall had at least doubled for most households which was a significant change from previous reports.
"But, to some extent, this reflects households being better prepared for retirement, allowing them to top up their superannuation payments to give them the lifestyle they want."
Transport was a big driver of spending increases, particularly for those living in the cities, while health care spending also rose.
Those who lived on a "choices" budget also spent more on recreation.
The report also looked at the household income of people over 65 and where their money came from using data from Statistics New Zealand's Household Economic Survey.
Matthews said it collected the data because its research showed people were spending more than what they were getting in NZ Super and it wanted to see where the money was coming from.
It found nearly half those who are spending an amount which gives them "choices" like buying a bottle of wine and eating out on a regular basis were still working either parttime or fulltime.
Matthews said she had been surprised by the proportion still working and the amount they were getting from doing so.
The average income from salary and wages for a single person living in the city was $300.90 for a no frills budget and $1053.60 for a choices lifestyle.
While a couple living in the city had an average income from salary and wages of $249.40 for a no frills budget and $1236.10 for a choices lifestyle.
Couples living on a no frills budget were the most dependent on NZ Super and other pensions with up to 93 per cent of their money coming from that.
Many over 65 year olds also got some form of income from investments although it was quite a small amount for some.
More than 75 per cent of those living a choices lifestyle had some income from investments.
Matthews said the research was helpful for younger people wanting to know how much extra to save to fill the gap between NZ Super and how much they wanted to spend in retirement.
"Looking at the gap is most useful because spending patterns are going to change. What people buy now might not be what people buy in the future."
The research found the shortfalls could be closed by people having a lump sum of between $21,00 to $783,000, depending on where they lived and what kind of lifestyle they wanted to have.
It also shows how much a 25-year-old would need to save per week to close the gap compared to how much a 50-year-old would have to save.
Matthews said those closer to retirement could use the spending data to work out a budget for how much it would cost them to live in retirement.
"In order to have flexibility and choice around employment during their retirement years, New Zealanders need to save during their working years to provide an income from investment to supplement NZ Superannuation, to fund their desired retirement lifestyle."
How much Kiwis spend in retirement (year to June 30, 2017)
Weekly NZ Super Rates One person household Two person household
Total weekly expenditure
No frills budget metro $590.44 $872.22
No frills budget provincial $561.04 $621.48
Choices budget metro $1175.17 $1399.72
Choices budget provincial $824.16 $1104.78
source: Retirement Expenditure Guideline Massey University Westpac Fin-ed Centre