Recently, BusinessDesk received an email from a reader seeking financial advice. It turns out her stepfather had some questionable suggestions for her and her husband. The reader and their husband earn around $150,000 pre-tax, have a huge mortgage of $600,000 and currently cannot contribute more than 3% to their KiwiSaver.

According to her stepfather, they should channel their KiwiSaver contributions into paying off the mortgage instead, arguing, “in the long run, loan interest is more than what we make off the employer/government contributions plus investment gains”.

Curious about the validity of this advice, BusinessDesk decided to crunch some numbers, and so did we. Assuming a 30-year repayment period, with ANZ’s average mortgage rate of 6.49%, and considering KiwiSaver funds usually yield an annual return of 7%, the couple would accumulate a staggering $410,567.20 after three decades. Even in a more conservative fund offering 3% annual returns, they would still amass $206,783.21. However, when they used ANZ’s mortgage calculator, it showed that they would only save $115,389 by paying off the mortgage which pales in comparison to the potential gains from KiwiSaver.

But where does this extra money from KiwiSaver come from exactly?

Here’s the deal: when you focus solely on the mortgage, you’re left to foot the bill by yourself. However, if you choose to contribute to your KiwiSaver, you not only put in your own money, but also receive contributions from the government (up to a certain limit) and your employer. You essentially have two other team members backing your financial journey.

But wait, there’s more.

As great as this sounds, there are still two major elephants in the room left to address; the choice of fund, and contribution rate. KiwiSaver providers usually offer at least five basic funds, ranging from conservative to high growth, with average returns ranging from 3% to 7%. Similarly, KiwiSaver allows you to contribute 3%, 4%, 6%, 8%, or 10% of your income, with a minimum pre-tax contribution of 3% from your employer. When you maximize both the fund selection and contribution rate, the differences in outcomes can be astonishing.

According to the numbers, if you go all-in and maximise your contributions while investing in the growth fund, you could potentially amass over $900,000 in gains after 30 years. That’s an astronomical figure that completely overshadows any savings you would get from paying off your mortgage.

Alas, this highlights just how crucial it is to understand the role KiwiSaver plays in your future. Considering that small changes compound to huge differences later in life, it is paramount to get on top of your KiwiSaver today.

Consider doing a KiwiSaver Health Check with us. It takes 5 minutes to change your future!

What's the reason not to get advice on you KiwiSaver account? Let National Capital help.

You may also like

Is Your KiwiSaver Ready for 2026?

If you want your KiwiSaver to genuinely support the life you’re planning for, this is the perfect moment to review

The Value of Financial Advice and What It Means for Your KiwiSaver

We wanted to share an interesting insight from Russell Investments’ 2025 Value of an Adviser report.

Investment Scam Alert: What Every Kiwi Needs to Know

Recently, the Financial Markets Authority (FMA) has warned of a surge in impersonator investment scams. These scams use fake ads

Are You Paying for KiwiSaver Advice You’re Not Getting?

Did you know? If you’re in a KiwiSaver fund, part of the fees you pay may already cover financial advice

What is KiwiSaver?

The answer to the question of what is KiwiSaver is a simple one. It is a voluntary investment scheme where

KiwiSaver Contribution Boost: What the 3.5–4% Increase Means for You

The government has announced that starting from 1 April 2026, the default KiwiSaver contribution rate for both employees and employers