Inflation is driving up the cost of a comfortable retirement for New Zealanders living on superannuation with as much as $1 million now required to bridge the gap.

The latest Retirement Expenditure Guidelines show the projected savings needed to live to the age of 90, on top of super payments, has increased.

Massey University's New Zealand Financial Education and Research Centre report shows a two-person household will need $831,000 for a comfortable city retirement, while in the provinces it costs $539,000.

A couple living a simpler life in the city needs $235,000, while a rural retirement will cost $120,000, on top of super payments.

Associate professor Claire Matthews says some people survived on NZ Super payments alone but most people could not.

The figures for a comfortable retirement includes money for travel, eating out and a higher standard of living compared to a no frills approach to life and spending.

"In the past year, the growing difference between NZ Super and weekly expenditure has been felt by all retirement household groups," says Matthews.

"While inflation has fallen compared to 12 months ago, it's still higher than recent experience and cost of living remains a big issue."

Matthews says the key drivers of costs over the past 12 months were food, recreation, culture, household utilities and insurance. She encouraged people to join KiwiSaver and put in more than the minimum payments.

"This is what our current retirees are spending," she says.

"Our current retirees have managed to save a reserve to spend at this level, which is reassuring."

However, she says costs would increase if people were renting in retirement rather than living in their own homes mortgage free.

"These guidelines reflect the current generation of retirees who are generally homeowners," she says.

"One of the things people need to think about it is what their housing situation is likely to be when they hit retirement.

"If you're in your 40s and 50s and still renting, it's likely when you hit your retirement that you will be renting.

"Therefore you need to allow for that in addition to what is in the guidelines."

 - RNZ.