Simplicity vs Kernel KiwiSaver 2026: Low-Fee Index Funds Compared (NZ)

Simplicity and Kernel are New Zealand's two low-fee index leaders at 0.24% and 0.25% p.a. Here is how their fees, fund range, ethical screening and returns actually compare in 2026.

By Henry Smith, Financial Adviser. Reviewed by Craig Smith, Principal Adviser, Smiths Financial (FSP712931), FMA Class 2 licence. Last reviewed 16 June 2026.

Simplicity and Kernel are New Zealand's two best-known low-fee index KiwiSaver providers. Both are passive index managers and both charge a fraction of what the big banks and active managers do. They are within a hair of each other on cost, so the real question is not "which is cheaper" but "which one fits the way you want to invest."

This guide compares them on fees, fund range, returns, ethical screening, tools, and who each one suits.

TL;DR: Simplicity vs Kernel at a glance

TL;DR: The headline fee gap is tiny — 0.24% p.a. (Simplicity) vs 0.25% p.a. (Kernel) — so the decision is about fit, not cost. Both are excellent low-fee index KiwiSaver providers. Simplicity charges 0.24% p.a. on its six diversified funds with no membership fee ¹¹⁰; Kernel charges 0.25% p.a. on core funds (0.45% on specialty) and offers 17 funds, including single-market index funds ²⁸. Pick Simplicity for a simple ready-made portfolio; pick Kernel if you want to build or tilt your own.

How are Simplicity and Kernel similar?

Before the differences, it helps to know why these two get grouped together. They share the features that matter most for long-term KiwiSaver growth:

• They are both low-fee passive index managers. Neither tries to pick winning stocks. They buy the whole market cheaply and let compounding do the work. On a $10,000 balance you pay roughly $24 a year with Simplicity and $25 with Kernel ¹⁰¹¹ — both far below the 1–2% p.a. that actively managed funds charge ¹¹.
• Neither charges a membership or admin fee. That flat dollar fee used to quietly punish smaller balances. Kernel removed its old $5/month member fee, and Simplicity has never charged one ¹².
• Both lean ethical. They screen out the usual exclusions and tilt towards responsible investment, rather than treating it as an add-on.
• Both are digital-first challengers, built to be cheaper and more transparent than the legacy bank schemes that still hold most of the country's KiwiSaver money.

For context on why fees matter this much: the FMA reported total KiwiSaver manager fees exceeded $780 million by 31 March 2024, with a market average near 0.8% ¹. On a $30,000 growth balance, the Sorted market average was around 1.05–1.07% p.a. in 2025 — four times what Simplicity or Kernel charge ⁶. Over 30 years, that difference is tens of thousands of dollars of your retirement. You can put your own numbers through our KiwiSaver growth calculator to see the gap on your balance.

How do the fees compare?

Management and membership fees

This is where most people start, and where the two are closest.

Simplicity dropped its diversified fee from 0.25% to 0.24% on 1 September 2025 — its seventh fee cut in seven years ¹. Kernel sits at 0.25% on its core index funds ². That 0.01% gap is about $3 a year on $30,000 — genuinely not a deciding factor.

The bigger point is the comparison against everyone else. Kernel's High Growth Fund charges 0.25% in total fund charges versus an 0.85% average for aggressive KiwiSaver funds — $75 a year on $30,000 against $254.60 for the average aggressive fund ⁷. Both providers are playing a different game from the banks.

The one fee nuance: Kernel's specialty funds run at 0.45% p.a. ². Still cheap by KiwiSaver standards, but if you load up on Clean Energy or Emerging Markets, your blended fee creeps above Simplicity's flat 0.24%.

How do the fund ranges and flexibility compare?

This is the real fork in the road, and it is more important than the fee difference.

Simplicity's diversified funds

Simplicity keeps it deliberately simple. It offers six diversified KiwiSaver funds — Defensive, Conservative, Balanced, Growth, High Growth (and a Default option) — all at the same 0.24% fee ¹⁰. Each is a ready-made, globally diversified portfolio with a set growth/income split. The Growth Fund, for example, runs roughly 80% growth / 20% income assets ⁶.

You pick one fund based on your risk appetite and timeframe, and you are done. There is nothing to build, rebalance or tinker with. For most KiwiSaver members — who should be in one well-diversified fund for decades — that is exactly right.

Kernel's single-market index funds

Kernel offers 17 funds within its KiwiSaver Plan, drawn from a range of 20-plus core index funds ⁸. Alongside multi-asset Conservative, Balanced and High Growth options, it has single-market and single-theme index funds you can mix yourself:

• S&P 500 (Unhedged and NZD Hedged)
• Global 100 and World ex-US (+ hedged versions)
• NZ 20, NZ 50 ESG Tilted, NZ Small & Mid Cap, NZ Commercial Property
• Australia 100, Global Infrastructure, S&P Global Dividend Aristocrats, Global ESG
• Specialty tilts like S&P Global Clean Energy and Emerging Markets (at 0.45%) ²⁸

This is the appeal of Kernel: you can build a portfolio with a deliberate tilt — say, a US-heavy or NZ-property slant — that you simply cannot construct inside Simplicity's diversified-only line-up.

The trade-off is responsibility. If you self-select single-market funds, you own the asset-allocation and rebalancing decisions. Most people do not need that, and a few get it wrong by chasing the fund that did best last year. For most members, the single-market range is a bonus rather than the reason to switch; picking one diversified fund and leaving it alone tends to work better.

How do the returns compare?

Returns are the question everyone asks and the one to treat most carefully. Past returns do not predict future returns, and the two providers report on slightly different bases, so compare like for like.

Using Sorted's Smart Investor (after fees and tax at the 28% PIR), the Simplicity Growth Fund returned 6.01% p.a. over the five years to 31 March 2026, versus a 4.96% average for growth KiwiSaver funds ⁶. Its most recent one-year return to the same date was 10.06% ⁶. On Simplicity's own site (before tax, after fees, to 31 May 2026), the Growth Fund shows 1-year 17.93%, 3-year 14.21% and 5-year 8.43% ¹³ — higher because it is a pre-tax, different-period figure. That is exactly why you should never compare a provider's own marketing return against another provider's after-tax Sorted figure.

Because the two providers publish their flagship numbers on different bases, we have split the like-for-like returns from the cost comparison below.

Returns on the same basis (after fees and tax, Sorted)

Cost comparison (annual charges on the same balance)

Note: Sorted's fund pages still listed Simplicity Growth at 0.25% at the time of writing, as Sorted's data lagged the 1 September 2025 cut; the current 0.24% management fee is sourced to Simplicity's own fee-cut announcement ¹.

Both sit at the low-fee, index end of the market, so over the long run their returns track their underlying markets minus a small fee — and that fee advantage is the most reliable edge either one gives you. The cleanest way to compare them on identical terms is the Sorted Smart Investor tool, which uses FMA Disclose Register data so every scheme is shown after fees and tax on the same basis ¹². You can also pressure-test your own setup with the free KiwiSaver health check or a KiwiSaver fund comparison.

How does the ethical screening and ownership compare?

Both providers screen, but their structures differ in a way some clients care about a lot.

Simplicity is a not-for-profit, owned by the Simplicity Foundation. It runs 100% online, invests most money passively across local and global markets, and donates 15% of its management fees to the Simplicity Foundation — over $14 million so far ⁹. For clients who want their fund manager's incentives pointed at members and the community rather than shareholders, that ownership model is a genuine differentiator.

Kernel applies ESG screening and offers explicitly tilted funds — its NZ 50 ESG Tilted and Global ESG funds let you dial up responsible-investment exposure if that is a priority, while keeping the rest of your portfolio in straight market-cap index funds ⁸. So Kernel's ethical angle is more "choose your level," whereas Simplicity bakes a baseline screen and a charitable structure into everything.

Neither is the "ethical" provider and the other the "unethical" one. They take different routes to a similar destination. If a charitable, not-for-profit structure matters to you, that points to Simplicity; if you want to deliberately tilt the ethical dial fund by fund, that points to Kernel.

How do the service, tools and first-home support compare?

Both are app- and web-first; there are no branches to walk into. Kernel's platform is built around its broader fund menu, with portfolio tools that suit members who want to combine funds and see their allocation. Simplicity's experience is streamlined to match its simpler product set — pick a fund, set your rate, done.

For first-home buyers, the mechanics are the same regardless of provider: KiwiSaver first-home withdrawal rules are set by legislation, not the scheme, so you can withdraw your eligible balance through either. What changes outcomes is fund choice and timeframe — a buyer 12 months out should usually not be in a High Growth fund with either provider. Getting the fund wrong in the two years before a purchase can cost more than a decade of fee savings, which is worth checking in a KiwiSaver review.

Worth knowing for 2026 planning: the annual government contribution was halved to 25c per $1, capped at $260.72, and you still need to contribute $1,042.86 of your own money between 1 July and 30 June to get the full amount ³. Members earning over $180,000 no longer qualify, and 16–17-year-olds became eligible from 1 July 2025 ⁴. The default contribution rate also rises from 3% to 3.5% from 1 April 2026 ⁵. None of this depends on whether you choose Simplicity or Kernel — but it affects how much you should be putting in either way.

Who does each provider suit best?

For the average member the choice is close enough that a 0.01% difference is not a reason to move on its own. Switching makes sense when you are leaving a high-fee bank scheme, or when one provider's fund structure genuinely fits your plan better. The KiwiSaver switching service handles the paperwork and the fund selection together.

Your switch-decision checklist

Before you move, run through these:

1. Check your current fee. If you are paying 1%+ at a bank, either Simplicity or Kernel is likely an improvement worth making.

2. Match the fund to your timeframe, not last year's return. Buying a first home soon changes everything.

3. Decide: ready-made or build-your-own. That single question settles Simplicity vs Kernel faster than any fee comparison.

4. Confirm your PIR. The wrong prescribed investor rate quietly costs you more than the fee gap between these two.

5. Compare on the same basis using Sorted Smart Investor — after fees and tax ¹².

6. Don't fragment. Splitting across two providers usually adds admin without adding diversification you couldn't get inside one.

Frequently asked questions

Is Simplicity or Kernel cheaper? Simplicity is marginally cheaper at 0.24% p.a. on its diversified funds versus Kernel's 0.25% on core funds, with neither charging a membership fee ¹². On a $30,000 balance that is about $3 a year — too small to be a deciding factor. Kernel's specialty funds cost 0.45%, so a specialty-heavy Kernel portfolio could end up dearer ².

Does Kernel let me choose my own funds? Yes. Kernel offers 17 funds in its KiwiSaver Plan, including single-market index funds like the S&P 500, NZ 20 and Australia 100, plus multi-asset Balanced and High Growth options ⁸. You can build a tilted portfolio. Simplicity offers six ready-made diversified funds only ¹⁰.

Which has had better returns? Comparisons must be on the same basis. Simplicity's Growth Fund returned 6.01% p.a. over the five years to 31 March 2026 after fees and tax, against a 4.96% growth-fund average ⁶. Because both are low-fee index managers, long-run returns mostly track their underlying markets minus fees. Compare them after fees and tax on Sorted Smart Investor ¹².

Are Simplicity and Kernel ethical KiwiSaver providers? Both screen responsibly. Simplicity is a not-for-profit that donates 15% of its management fees to the Simplicity Foundation ⁹. Kernel offers ESG-tilted funds such as NZ 50 ESG Tilted and Global ESG so you can dial up responsible exposure ⁸. The ethical structures differ rather than one being "ethical" and the other not.

Should I switch from my bank KiwiSaver to one of these? Often, yes — if you are paying around 1% or more, moving to a ~0.24–0.25% index provider can save tens of thousands over a working life ¹⁷. The bigger risks are being in the wrong fund for your timeframe and an incorrect PIR. A quick review confirms whether switching is right for you.

Can I use either provider for a first-home withdrawal? Yes. First-home withdrawal rules are set by legislation and apply to both providers equally. What matters more is being in a fund that suits your purchase timeframe — a High Growth fund 12 months before buying carries real risk with either.

General information, not personalised financial advice. Seek advice tailored to your situation before acting. Craig Smith Business Services Ltd (FSP712931), trading as Smiths Financial, holds a Class 2 licence issued by the Financial Markets Authority and is a member of the Financial Dispute Resolution Service (FDRS). Written by Henry Smith, Financial Adviser; reviewed by Craig Smith, Principal Adviser. Last reviewed 16 June 2026.