Why Living to 100 is Your Greatest Financial Risk

We plan for the worst-case scenario in the markets, yet we rarely plan for the best-case scenario in our health: living twenty years longer than previous generations.

For decades, we were sold a dream template for life: work for 40 years, then spend 15 years in retirement before a quiet exit. This three-stage model of learn, earn, and retire is mathematically fragile in a world where reaching 100 might be a standard outcome rather than a statistical outlier.

If you retire at 65 and live to 100, you must fund 35 years of consumption without a salary. That is nearly as long as you spent working. Relying on a traditional, conservative investment approach to fund almost four decades of retirement is a reliable path to running out of money before you run out of years.

The Death of the Hard Stop

The concept of age 65 as a mandatory finish line is an industrial-era relic. It was popularised when manual labour was the norm and life expectancy was considerably lower. Today, for many New Zealand professionals, the mind remains sharp well after the body starts slowing down.

A 100-year life demands a multi-stage approach. Instead of a cliff-edge retirement, we are seeing the rise of career breaks, "protirements," and mid-life pivots. If you know you have a 60-year career ahead of you, taking two years off at 45 to retrain, travel, or spend more time with the kids seems less like a distraction and more like a necessary maintenance interval.

Maintaining earning longevity is the ultimate hedge against inflation. If you can provide value to the job market in your 70s, even part-time, you drastically reduce the pressure on your liquid assets. The goal should be to maintain your human capital just as aggressively as your financial capital. It is much easier to fund a long life when you are still bringing in some revenue.

What Does Retirement Actually Cost in New Zealand?

Before worrying about how to invest for a long retirement, it helps to know what you are actually funding.

Massey University's Fin-Ed Centre publishes annual Retirement Expenditure Guidelines based on actual spending data from retired New Zealanders. The 2025 figures give a clear picture of what different retirement lifestyles genuinely cost.

For a two-person household in a metropolitan area, a "no frills" retirement covering basic living with few luxuries costs around $910 per week. A "choices" retirement, representing a more comfortable standard of living with modest travel and leisure, costs around $1,740 per week. In provincial areas the figures are lower, roughly $1,030 per week for no frills and $1,210 for choices.

NZ Super (often just called “the pension”) for a couple currently pays around $800 per week after tax. The gap between what Super provides and what retirees actually spend ranges from roughly $110 per week at the lower end to over $940 per week for a couple living comfortably in a main centre.

To fund this gap over 25 years of retirement, Massey's research estimates couples need a lump sum at age 65 ranging from around $120,000 for a no-frills provincial retirement to over $1 million for a comfortable metropolitan one. For singles, the figures range from roughly $46,000 to $516,000.

These figures are based on today's costs and assume Super continues at its current rate. If you are planning for the possibility of living to 100, a 35-year retirement rather than 25, the required savings increase substantially. This is the core reason why a well-structured investment plan, not just savings, is essential for anyone approaching or already in retirement.

Inflation: The 40-Year Erosion of Purchasing Power

Most retirees fear market volatility. They see a 10% dip in the headlines and panic. The real threat, however, is the slow and invisible erosion of purchasing power.

Over a 35-year period, even modest inflation can cut the value of a dollar in half, then half again! If you shift your entire portfolio into term deposits or bonds the moment you turn 65, you are essentially guaranteeing a declining standard of living by your mid-80s.

To survive to a century alongside you, your portfolio must remain growth-oriented long after you stop working. You need assets growing faster than the cost of living in 2055. This requires a permanent allocation to equities. Bonds might offer comfort during a market downturn, but they rarely provide the compounding growth needed to fund a four-decade retirement.

If you are 65 today, your money may still need to work for another 35 years. That is a longer time horizon than many 30-year-olds hold for their first home deposit. Treat it accordingly.

The New Zealand Reality: Super, PIE, and Tax Drag

NZ Super provides a floor, not a ceiling. As noted above, it currently pays around $472 per week net for a single person and around $800 combined for a couple. It will prevent genuine poverty, but it will not fund the healthcare or travel expectations of an active retiree. The real issue for higher earners is not the existence of Super, but its limited relevance to their actual cost of living.

New Zealand's tax environment does favour certain structures, particularly Portfolio Investment Entities (PIEs). Because PIE tax rates are capped at 28%, they are often more efficient than holding assets in your personal name, especially if you remain in the 33% or 39% bracket due to other income or ongoing consulting work. Over a 35-year retirement, the compounding effect of a lower tax rate on investment returns is substantial and worth structuring for deliberately.

Worked Example: The Cost of the Final Decades

Consider Sarah and Simon, both aged 65. They have worked and saved hard to accumulate a combined KiwiSaver and private investment portfolio worth $1.5 million. They need around $100,000 per year to maintain their lifestyle. NZ Super covers approximately $41,000 of that, so their portfolio must fund the remaining $60,000 per year, growing at 3% annually to keep pace with inflation.

On the conservative path, their money sits in term deposits earning 2% after tax (for ease, let’s exclude inflation from the calculation too, otherwise the real rate of return on the term deposits might be negative!). Their term deposit portfolio is exhausted around age 88. From that point, they live entirely on NZ Super, with no capacity to fund private healthcare, family support, or the unexpected costs that come with advanced age.

On the growth path, they maintain a diversified portfolio earning 4% after tax. Their portfolio still holds approximately $200,000 at age 100. They retain their financial independence throughout, with the flexibility to cover healthcare, help family members, or simply enjoy the life they worked for.

The difference is not how much they saved. It is what they owned. Two percentage points of additional annual return, compounded over 35 years, is the difference between running out of money in your late 80s and never running out at all.

It is worth noting that $1.5 million at retirement is well above the median for New Zealand households. For a couple retiring with $600,000, the same principles apply with less margin. At that level, the conservative path exhausts the portfolio before age 80, leaving over two decades dependent entirely on NZ Super.

Clearly this is a simple example just for the purposes of illustration which doesn’t include factors such as inflation, or the desire to spend more during the early retirement years. Plus, there is an added dimension for couples: New Zealand women outlive men by an average of 3.4 years, and because wives are typically a year or two younger than their husbands, many women will spend five or more years as a widow, funding retirement alone on the single NZ Super rate of around $472 per week rather than the $800 couples rate, which makes a well-structured investment portfolio even more critical for women specifically.

Health Span Versus Wealth Span

Trust us when we say there is a particular irony in financial planning: the people best at saving money are often the worst at spending it. They spend 40 years building a wealth span while neglecting their health span.

Living to 100 is only meaningful if you remain mobile and cognitively sharp for most of it. From a financial planning perspective, this means investing in your health early. Private medical insurance in New Zealand becomes expensive in your 70s and 80s, but it remains a critical tool for bypassing public waiting lists for quality-of-life procedures. Current Ministry of Health data shows median wait times for elective procedures like hip replacements and cataract surgeries can exceed 12 to 18 months in the public system.

You should also plan for the fourth stage of life: the period requiring intensive or residential care. You cannot predict whether you will need a premium care suite in a retirement village, but you can predict it will not be cheap. Current daily rates for high-level care regularly exceed $200 per day above the government subsidy for those with assessable assets.

How to Prepare for a Century: A Practical Summary

Reframe what risk actually means. Risk is not a falling share price. Risk is being 85 years old and running out of money.

Audit what you own. Do you hold a high-quality, diversified portfolio, or are you holding assets unlikely to survive a decade of economic change?

Optimise your tax position. Tax efficient structures such as PIE funds can matter over long periods. Ensure you are using them where appropriate.

Extend your time horizon. Even at 60, stop looking at five-year projections. You are playing a 35 to 40-year game.

Frequently Asked Questions

Is NZ Super enough to live on?

For most urban professionals, no. At around $472 per week for a single person and $800 combined for a couple, it is designed to prevent poverty rather than maintain a comfortable lifestyle. Think of it as a subsidy for your existing investments rather than a primary income source.

Should I pay off my mortgage before investing for longevity?

The traditional answer is yes, because a debt-free home reduces your baseline cost of living significantly.

However, do not let mortgage repayment prevent you from starting to build a liquid, compounding portfolio alongside it. You cannot access equity in a crisis with the speed you can access a diversified investment portfolio or managed fund.

What is the 4% rule and does it work in New Zealand?

The 4% rule suggests you can withdraw 4% of your initial portfolio value annually without running out of money. While a reasonable starting point, it was based on older US historical data and shorter retirement horizons. For a 100-year life, a variable withdrawal approach, spending less when markets are down, is considerably safer.

Will NZ Super change?

New Zealand is facing a retirement reckoning. With a rapidly ageing population and a pension system designed for a much shorter lifespan, the question isn't if changes will come, but when, how, and what. As a result, it will be considerably harder to resolve the complex financial challenges that rising longevity presents, not least of all the affordability to the taxpayer of sustaining NZ Super, which is one of the most generous in the world as it is not means-tested.

How Long Will You Live?

While it’s impossible to know precisely how long we’ll live, research shows:

• ‍Kiwis are living longer and life expectancy increases for each additional year we live.‍
• Women tend to live longer than men.
• There are disparities in life expectancy between the rich and poor. Life expectancy is reduced in lower socio-economic areas in New Zealand and in the early 2010s there was an eight-year life-expectancy gap for men and a six-year gap for women between the least and most deprived neighbourhoods.‍
• Famously, billionaires are investing in the quest for eternal life.

The Bottom Line: Can You Live to Age 100?

Living to 100 is no longer exceptional. It is a genuine planning probability.

The traditional advice of slowing down and moving to safety at 65 is built on assumptions about life expectancy that no longer hold. If you want your money to last as long as you do, you need to own high-quality assets, understand what retirement actually costs in New Zealand, and resist the false comfort of excessive conservatism.

Stop planning for a retirement that ends at 80. Plan for one that reaches 100, and make sure your portfolio is robust enough to fund the whole journey.

Your money might need to last 35 years after you stop working for it. Does your current trajectory reflect that? Book a complimentary conversation with one of our advisers to find out.