People who want to have choices in retirement will need to have around $100k in their KiwiSaver account by age 30 to be on track, figures from Massey University show.

Numbers crunched by Massey University have revealed how much an individual would need to have in KiwiSaver by age 30, 40, 50 and 60 to afford either a no-frills retirement or more choices.

The figures are based on Massey University's annual retirement expenditure guidelines which show a one-person household would need to have $101,774 saved by age 65 to live a no-frills life in the city or just $30,199 in the provinces.

To be on track for a 'no frills' retirement a person would need to have $25,000 in their KiwiSaver account by age 30, $45,500 by 40 and $66,500 by age 50.

To get there a person would need to save roughly $36.42 a week from the age of 18 until they retire at 65.

But those wanting more choices in retirement - to buy a bottle of wine, go on holiday or just see a movie - would need much more.

Massey's figures show a one-person household would need to have $360,620 in savings by age 65 for those in the city and $388,073 for those in the provinces.

To have $400k in savings by age 65 a person would need to have $101k by 30, $182k by 40, $266,500 by 50 and $354k by age 60.

That would require a person to save just over $145 a week from age 18 until age 65.

If you want to retire on a 'comfortable' amount of savings, many Kiwis will need to be saving much more than they currently are. (Photo \ 123RF)

The calculations assume the money is invested in a balanced KiwiSaver fund with a net return of 2.4 per cent per year.

Claire Matthews, a KiwiSaver expert at Massey University who produces the retirement expenditure data and crunched the age-data, said the figures assumed people's lives went in a straight line and they started saving at age 18 and kept saving the same amount throughout their lives.

"The reality is they should be able to pick up their savings."

"What you earn at 18 is going to rise."

Matthews said people should be able to save more as their pay increased but should also be aware that even saving a small amount early could have a substantial impact on their lump sum at retirement.

She pointed to recent figures by AUT University which showed a person earning $40k a year who saved 3 per cent from age 18 could have $1.16 million by 65 including employer and government contributions.

That assumed the person invested their KiwiSaver account in a growth fund and had an annual average after tax and fees return of 7.5 per cent.

But a person who waited to start saving until age 30 would have just $428,000.

Matthews also worked out how much a person would need to save if they emptied their KiwiSaver account to buy at a house at age 30.

To get to $100k for a 'no frills' retirement they would need to put away nearly $50 a week after age 30 and for a choices retirement they would need to save around $200 a week to get to $400k.

"I have always argued that withdrawing funds up to the age of 30 is fine but people have to adjust their savings."

"They have got to recognise they have lost those 12 years."

Matthews said a typical lifetime could see people save while they were young, drop their savings rate when they bought a house and had a family and then increase it again when their mortgage was paid off and the children became independent.

She urged those starting out in the workforce to start saving into KiwiSaver from the get-go.

"The moment you start a job start saving, and don't do the minimum 3 per cent."

"If you start saving when you get your first pay you are not going to notice it because you never had it."

She recommended people start saving at 8 per cent of their salary which could then be dropped down to 4 per cent or 3 per cent when money got tighter when they had a mortgage and/or a family.

It made sense to increase the saving rate again when more cashflow became available, she said.

"At the moment it is really advantageous to go into retirement in your own home, mortgage-free."

That meant it was better to get onto the property ladder sooner rather than later.

Matthews said ideally it was also better to buy a home without using your KiwiSaver savings but she doubted that was realistic for those living in the main centres.

She said people who emptied their KiwiSaver account to buy a first home needed to continue to save for their retirement.

"If you are not saving in KiwiSaver, your employer is not putting in their contribution and you'll be missing out on the government contribution as well."

Matthews said her figures took a conservative approach and a higher return on investment could make quite a bit of difference when it came to boosting savings.

The amount a person had at retirement could also be boosted by one-off lump sums from down-sizing a property, moving to another area or an inheritance.