A couple wanting to live in a major city and have a comfortable retirement would need to save a lump sum of $785,000 at retirement - and have a mortgage-free home, research has revealed.

Analysis by the Westpac Massey University Fin-Ed Centre of spending by over 65-year-olds in the year to June 30, 2018, shows virtually all spent more than what they get from the government in New Zealand Superannuation.

Claire Matthews, who carried out the research, told Mike Hosking while that money might seem like a lot, it's split between two people.

"It's for two people so it doesn't make it a lot easier but it does simplify it."

The difference between urban and country living was stark with a two-person household living regionally only needing $494,000 to comfortably retire.

Matthews said there are a number of reasons why it's cheaper to live outside big cities.

"It partly reflects choices in lifestyle as well because if you're living in the city, to some extent you probably have more choices around things to do...because there are just more activities going on so you can go to more things. Whereas if you're living in the provinces you don't necessarily have the same opportunities."

She said those numbers become more affordable the earlier you start saving.

"If you can start as you start work and start saving then those numbers are very easily affordable."

Matthews said the figures confirmed that NZ Super was not enough to fund the retirement most people want.

"While living on New Zealand Super is possible, for the vast majority of New Zealanders it doesn't support the lifestyle they wish to have.

"This reinforces the need to save for retirement if you want to set yourself up to have the retirement you want."

A couple living a no frills lifestyle in the provinces were able to get by mainly living on NZ Super but would still require a lump sum of around $13,000 at retirement to fund their spending.

Matthews said the fact that the spending of today's retirees exceeded NZ Super showed they had prepared well by either having savings or continuing to work to support themselves.

But she said future generations may not be as prepared.