How accurate is this KiwiSaver calculator?

The KiwiSaver calculator uses standard compound interest formulas with assumptions about constant salary, contribution rates, investment returns, fees and tax (PIR). Real-world results will differ due to salary changes, contribution holidays, market volatility and provider-specific fees. Treat the projection as an estimate, not a guarantee.

Does the calculator include the KiwiSaver government contribution?

Yes. The calculator includes the annual government contribution of up to NZ$521.43 per year, assuming you contribute at least NZ$1,042.86 in that year and are eligible. You can toggle the government contribution on or off to see the impact.

Which KiwiSaver contribution rate should I choose?

Employees can usually choose 3%, 4%, 6%, 8% or 10% of their gross pay. A higher rate increases your long-term balance but reduces your take-home pay. Many people start at 3% and increase later as income grows. Use the calculator to compare different rates and see how much extra you could have at retirement.

What investment return should I use for KiwiSaver?

Conservative funds may return around 2–4% after fees and tax over the long term, balanced funds around 3–5%, and growth funds around 4–7%. No return is guaranteed. It is safer to use a conservative estimate than an optimistic one when planning for retirement.

Does the calculator adjust for inflation?

By default the calculator shows nominal dollars, not inflation-adjusted dollars. You can optionally enter an inflation rate to see an approximate real (today's dollars) value of your projected KiwiSaver balance.

KiwiSaver Calculator (New Zealand)

Estimate your future KiwiSaver balance, including employee, employer and government contributions, investment returns, fees and tax (PIR). Compare scenarios and see how small changes today can grow your retirement savings.

KiwiSaver projection tool

Current age (years)

Retirement age (years)

Gross annual salary (NZ$)

Expected salary growth (% per year)

Contributions

Employee contribution rate (% of salary)

Employer contribution rate (% of salary)

Default is 3% minimum employer contribution (before ESCT and any scheme fees).

Include government contribution (up to NZ$521.43/year)

Current KiwiSaver balance (NZ$)

Investment settings

Expected annual investment return (% before tax & fees)

Use a lower rate for conservative funds and higher for growth funds.

Annual fee (% of balance)

Includes management and administration fees.

Prescribed investor rate (PIR)

Check your PIR with your provider or Inland Revenue.

Inflation rate (% per year, optional)

Used to show an approximate balance in today's dollars.

Results

Enter your details above and click Calculate KiwiSaver projection to see your estimated balance.

How this KiwiSaver calculator works

This tool models your KiwiSaver account using yearly compounding. It includes:

Employee contributions (a percentage of your gross salary)
Employer contributions (before ESCT, simplified)
Government contribution (up to NZ$521.43 per year if eligible)
Investment returns, fees and tax (PIR) on the balance
Optional salary growth and inflation

Core formula

For each year, the calculator:

Updates your salary with salary growth (if any).
Calculates annual contributions:
Employee contribution = salary × employee rate
Employer contribution = salary × employer rate
Government contribution = min(521.43, 0.5 × employee contribution) if enabled
Adds contributions to your balance.
Applies investment return, fees and tax:
Gross return = balance × return rate
Fees = balance × fee rate
Tax on return = max(gross return, 0) × PIR
Net growth = gross return − fees − tax
New balance = balance + net growth

This repeats for every year until your chosen retirement age.

Nominal vs real (inflation-adjusted) dollars

The main projected balance is in nominal dollars (future dollars). To estimate the value in today's terms, we discount by inflation:

Real balance ≈ Nominal balance ÷ (1 + inflation rate)^years

Choosing realistic assumptions

Investment return

Conservative fund: 2–4% per year
Balanced fund: 3–5% per year
Growth/aggressive fund: 4–7% per year

These are long-run, after-fee, after-tax ranges based on historical data. Markets are volatile, so no return is guaranteed.

Fees

KiwiSaver fees vary by provider and fund type. Typical total fees (management + admin) range from about 0.3% to 1.3% per year. Lower fees can significantly increase your long-term balance.

PIR (Prescribed Investor Rate)

Your PIR depends on your taxable income in the last two years. Common rates are:

10.5% – lower income
17.5% – middle income
28% – higher income

Using the wrong PIR can mean paying too much or too little tax. Always confirm your PIR with Inland Revenue or your provider.

Limitations and important notes

The calculator assumes continuous employment and contributions with no contribution holidays.
Employer contributions are modelled before ESCT; actual employer tax may reduce the amount invested.
Government contribution rules (eligibility, residency, age) are simplified.
Investment returns are assumed to be smooth and constant, but real markets fluctuate.
This tool is for education and planning only and is not financial advice.

KiwiSaver calculator – frequently asked questions

Is this KiwiSaver calculator official?

No. This is an independent educational tool. For official information on KiwiSaver rules, eligibility and tax, refer to Inland Revenue (IRD), the Financial Markets Authority (FMA), and the New Zealand government websites.

Can I model a one-off lump sum contribution?

At the moment this calculator focuses on regular salary-based contributions. To approximate a lump sum, you can temporarily add it to your current balance and run the projection, then compare with and without the lump sum.

What if I take a contribution holiday?

The calculator assumes continuous contributions. To approximate a contribution holiday, you can lower your employee contribution rate for the relevant period and re-run the calculation, or reduce your average annual contribution manually.

Does this calculator handle first home withdrawals?

No. First home withdrawals and other early withdrawals are not modelled. If you plan to withdraw for a first home, you can estimate the impact by subtracting the expected withdrawal from your projected balance at the time of withdrawal and then re-running the projection from that lower balance.

Should I increase my KiwiSaver contribution rate?

Increasing your contribution rate generally increases your retirement balance, but reduces your take-home pay. Use the calculator to compare 3%, 4%, 6%, 8% and 10% contributions and consider your budget, debt, and other savings goals. For personalised advice, speak with a licensed financial adviser.