When should you start saving for retirement in New Zealand?

Ask a financial adviser when you should start saving for retirement and the answer will always be the same: as early as possible. It's good advice, but it's not always the most useful thing to hear — particularly if you're reading this in your 40s or 50s and feeling like that ship has already sailed.

So let's look at what the numbers actually show, and what "starting now" genuinely means at different life stages. If you haven't yet worked out how much you'll actually need, that's a good place to start.

The power of compounding — and why starting early matters so much

Compounding is the process by which your savings generate returns, and those returns then generate their own returns. Over time, it produces results that feel almost counterintuitive.

Consider two people. The first starts contributing $200 per month at age 25 and stops at 35 — just ten years of saving, then nothing more until retirement at 65. The second waits until 35 and contributes the same $200 per month all the way through to 65 — thirty years of consistent saving.

Assuming the same average return, the first person — who saved for a third of the time — ends up with more. The decade of head start, and the extra years for those early savings to compound, outweighs three decades of later contributions.

This is not an argument for stopping saving after ten years. It's an illustration of how dramatically time affects outcomes — and why every year of delay has a real cost that money alone can't easily recover.

What starting in your 20s looks like

If you're in your 20s, the most valuable thing you can do is simply start — and make sure your KiwiSaver is set up and contributing. At this stage, the amounts matter less than the habit and the time. Even contributing at the default rate of 3.5% on an early career salary, and leaving it alone, produces a meaningful balance over 40 years.

The other opportunity at this stage is lifestyle. The spending patterns people establish in their 20s tend to persist. Someone who develops a conscious relationship with money early — spending on what genuinely matters, saving the difference — builds retirement security almost as a byproduct of simply living well. The compounding works on savings behaviour as much as it works on money.

What starting in your 30s looks like

Your 30s are typically when retirement starts to feel real rather than theoretical — career is more established, income is higher, and there may be a mortgage, a partner, or children in the picture. This is also often when KiwiSaver balances become visible enough to pay attention to.

The key lever at this stage is contribution rate. Moving from 3.5% to 6% or 8% of salary makes a significant difference over 30 years — for a full picture of how contribution rates affect retirement outcomes, see Is KiwiSaver enough to retire on? ThatDay can show you instantly what that difference looks like in your specific situation. Many people in their 30s are also in a position to begin examining their spending more intentionally — and to discover that reducing it meaningfully is both more achievable and more rewarding than they expected.

What starting in your 40s and 50s looks like

This is where most retirement planning articles either panic the reader or offer vague reassurance. Neither is particularly useful. The honest picture is this: starting later means the maths is harder, but it doesn't mean the goal is out of reach.

There are two things working in favour of people in their 40s and 50s that weren't available earlier. First, income is typically at or near its peak, which means the capacity to save is often greater than at any previous point. Second — and this is where conscious spending becomes particularly powerful — there is usually more discretionary spending to examine. The lifestyle that made sense at 35 may contain a significant amount that, on reflection, isn't adding much to daily life. Redirecting even a portion of that spending can have a much larger effect on the retirement timeline than most people expect.

ThatDay is particularly useful at this stage because it shows not just the gap between where you are and where you need to be, but what different saving and spending scenarios do to that gap. Seeing those numbers move in real time tends to make the choices feel concrete rather than abstract.

The cost of waiting

If there's one number worth sitting with, it's this: every year of delay doesn't just mean one less year of saving. It means one less year of compounding on everything you would have saved. The cost of waiting grows the longer you wait.

This isn't meant to induce anxiety — it's meant to make "starting now" feel genuinely urgent in a useful way. Whatever your age, whatever your current balance, the best time to understand your retirement picture clearly is today. Not because it will be comfortable, but because knowing is always better than not knowing — and because the gap between where you are and where you need to be is almost always more achievable than people fear.

Find out where you stand

ThatDay is a free retirement planning platform built for New Zealanders. It will show you exactly where you stand today, what you need to reach your retirement goal, and what different savings and spending choices do to that picture — at any age, and for individuals or couples.

Its financial assumptions were independently validated by the University of Auckland Business School's Master of Applied Finance programme. ThatDay is free for every New Zealander to use.

See where you stand today — start your free plan at thatday.co.nz