How the KiwiSaver tools work.
Sources, methodology, and the assumptions behind every projection.
QUESTIONS
Frequently asked questions
What are the KiwiSaver rate changes coming in?
From 1 April 2026, the default employee KiwiSaver rate moves from 3% to 3.5%. From 1 April 2028, it moves to 4%. Employer matching tracks alongside.
You can still elect 3%, 4%, 6%, 8%, or 10% manually. The default only applies if you've never changed your rate.
How is the long-term projection calculated?
Year by year, we add your contributions (employee + employer net of ESCT + government top-up), apply the assumed return rate for your fund type, and deduct the annual fund fee. Salary grows by the rate you set; the contribution percentages stay constant unless the legislated schedule kicks in.
Returns are 10-year NZ averages by fund type. Past returns aren't a guarantee of future returns — the projection is a useful frame, not a forecast.
How accurate is the fund comparison data?
Fees, returns, and fund metadata are sourced from each fund's public Disclosure Statements and Sorted's Smart Investor listings. Each row links to the source. We refresh the seed periodically (last refreshed date shown on the row) and aim for a Disclose Register API integration in production. Always check the source link before making decisions based on a specific fund.
Why don’t you say which fund is “best”?
“Best” depends on your time horizon, risk tolerance, what else you hold, your tax situation, and how you feel about responsible investing — questions a comparison page can't answer for you. We list alphabetically by default and let you sort by fee, return, or risk-adjusted return when you want to look harder. For tailored advice, see a licensed financial adviser.
What about ESCT and the government contribution?
ESCT (Employer Superannuation Contribution Tax) is taken off the employer contribution at your bracket-specific rate — the number that lands in your KiwiSaver is net of ESCT. We apply the right ESCT rate to your projection automatically.
The government tops up your KiwiSaver by 25 cents for every dollar you contribute up to a cap (currently $260.72 per year if you've contributed at least $1,042.86). The cap doesn't apply if your income is over $180,000.
Are these tools advice?
No. These are educational calculators. They apply public rules and assumed return rates to the numbers you give them. For advice tailored to your situation, see a licensed financial adviser.
PROJECTION ASSUMPTIONS
How we calculate this.
Why might my BetterMoney projection differ from my provider’s app?
Most NZ KiwiSaver providers — Simplicity, Generate, Booster, AMP, ANZ — show your projected balance in today's dollars (also called “real” or “inflation-adjusted”) on their annual member statements. This is what the FMA mandates: it shows what your future balance will buy at today's prices, accounting for the cost of living going up.
BetterMoney supports both views. By default we show today's dollars — matching your provider. Toggle to “future dollars” to see the larger nominal number you'll actually read on a statement decades from now.
The two views answer different questions and use different methods. They aren't the same calculation viewed two ways — they're two different projections that produce results in different units. See “What return assumptions do you use?” below for the specifics.
What return assumptions do you use, and where do they come from?
Two sets of rates, one for each view. Both are sourced from public NZ industry data — never made up.
Today's dollars (real mode) — FMA Projection Standards:
| Fund | Real return |
|---|---|
| Defensive | 1.5% |
| Conservative | 2.5% |
| Balanced | 3.5% |
| Growth | 4.5% |
| Aggressive | 5.5% |
These are the rates the Financial Markets Authority requires every licensed KiwiSaver provider to use in your annual member statement. They're already net of fees, net of 28% PIR tax, and adjusted for 2% inflation. Salary growth assumed at 3.5% per year. Source: FMA's KiwiSaver projections page and the Government's projection-information notice. By using these unchanged, BetterMoney's “today's dollars” projection lines up with what your provider will show.
Future dollars (nominal mode) — Morningstar NZ baseline, forward-tempered:
Step 1 — the Morningstar NZ 10-year category averages (gross returns, before fees, before tax) to 30 June 2025:
| Morningstar category | 10-yr return |
|---|---|
| Conservative | 4.1% |
| Moderate | 4.6% |
| Balanced | 6.4% |
| Growth | 7.8% |
| Aggressive | 8.6% |
Source: Morningstar KiwiSaver Survey, June Quarter 2025.
Step 2 — BetterMoney tempers these forward by ~0.6–0.9 percentage points to reflect that the past decade was an exceptional one for global equities (post-GFC bull market, low bond yields, high valuations). Forward-looking estimates from KiwiSaver actuaries and asset managers typically apply this kind of tempering. The tempered, locked BetterMoney nominal table is:
| Fund | Locked nominal | vs Morningstar |
|---|---|---|
| Defensive | 3.0% | Morningstar doesn't publish; derived |
| Conservative | 4.0% | Morningstar 4.1% (essentially matches) |
| Balanced | 5.5% | 0.9pp lower than Morningstar's 6.4% |
| Growth | 7.0% | 0.8pp lower than Morningstar's 7.8% |
| Aggressive | 8.0% | 0.6pp lower than Morningstar's 8.6% |
These are gross returns. Your stated annual fee is deducted separately from this; PIR tax is not modelled in nominal mode (we surface this as “gross account growth”). You can override the return rate, fee, and salary growth in advanced settings.
Why the gap between the two views? Real mode uses FMA's net-of-fees-and-tax rates; nominal mode uses gross rates with user-controlled fee. The two methods answer different questions. They will not produce numbers that are perfect arithmetic conversions of each other. Both are honest views; pick the one that's useful for the decision you're making.
Reviewed annually alongside the FMA's notice updates and Morningstar's June-quarter survey. Past performance doesn't guarantee future returns — these are estimates, not promises.
What inflation and salary assumptions do you use?
Inflation: 2.0% per year — the midpoint of the Reserve Bank of New Zealand's 1–3% target band, and what the FMA prescribes for projections.
Nominal salary growth: 3.5% per year — also the FMA-prescribed assumption.
Real salary growth (used in today's-dollars mode): 1.5% per year — derived from 3.5% nominal minus 2% inflation.
All overridable in advanced settings.
Why don’t you model PIR tax in future-dollars mode?
Future-dollars mode is designed to show “gross account growth” — what the underlying investments earn before tax. PIR tax (typically 10.5%, 17.5% or 28% depending on your income) is then paid annually within the fund. We don't model this for two reasons: (1) PIR rates differ per member and modelling it accurately would require extra inputs that complicate the tool; (2) today's-dollars mode already uses FMA rates that bake in 28% PIR, so users wanting a tax-realistic projection should use that view. We may add explicit PIR modelling in a future update.