NZ KiwiSaver Calculator: What Your KiwiSaver Grows To
Work out what your New Zealand KiwiSaver grows to from your current balance plus regular monthly contributions — the long-run compounding that builds retirement (and first-home) savings under KiwiSaver.
Adjust the inputs and select Calculate for a full breakdown.
Year-by-year growth schedule
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Future value | Total contributions | Total interest earned |
|---|---|---|---|
| $15k + $400/mo · 6% · 20yr | $234,469.43 | $111,000.00 | $123,469.43 |
| $0 + $300/mo · 7% · 35yr | $540,316.38 | $126,000.00 | $414,316.38 |
| $60k + $600/mo · 6% · 15yr | $321,736.84 | $168,000.00 | $153,736.84 |
| $5k + $250/mo · 6% · 25yr | $195,573.34 | $80,000.00 | $115,573.34 |
How This Calculator Works
Enter your current KiwiSaver balance, total monthly contributions (your own plus your employer's), the return you expect, and the years invested. The calculator compounds the balance monthly and shows the projected balance and how much is investment growth.
The Formula
Future Value with Regular Contributions
P = starting amount, PMT = monthly contribution, r = monthly rate (annual ÷ 12), n = number of months
Worked Example
A $15,000 balance plus $400 a month (your contributions plus employer's) for 20 years at 6% grows to about $234,469 — with roughly $123,469 of that being investment growth. KiwiSaver is New Zealand's voluntary workplace savings scheme: you contribute a percentage of your pay (you choose your rate — commonly 3%, 4%, 6%, 8%, or 10%), your employer contributes at least a set minimum, and the government adds an annual contribution if you meet the minimum personal contribution. This projection captures the core compounding; the government top-up and fund fees/tax are extra factors.
Key Insight
KiwiSaver is the cornerstone of retirement saving for most New Zealanders, with several 'free money' boosts that make engaging with it worthwhile. The contribution sources stack: you pick a contribution rate as a percentage of your gross pay (typically 3%, 4%, 6%, 8%, or 10%), your employer must contribute at least a set minimum percentage on top (effectively extra pay you only get if you're contributing), and the government adds an annual contribution (the 'government contribution' or member tax credit) up to a cap if you contribute at least the qualifying minimum each year — so not contributing enough to capture the full employer and government contributions leaves money on the table. Key choices that drive the outcome: your fund type (defensive/conservative/balanced/growth/aggressive) hugely affects long-run returns — younger savers with decades to go often benefit from a growth fund, while those near retirement or a first-home withdrawal may want lower volatility; and fees, charged as a percentage of your balance, compound against you over decades, so a low-fee provider matters. KiwiSaver returns are taxed via the PIE (Portfolio Investment Entity) regime at your prescribed investor rate, which this simple projection doesn't deduct. Two big uses: retirement (you can generally withdraw at the age of NZ Super eligibility) and a first-home withdrawal (you can withdraw most of your balance toward a first home after a qualifying period, plus possible HomeStart grant). This calculator captures the core compounding of your and your employer's contributions; for a fuller picture add the annual government contribution and account for your fund's fees and PIE tax. The biggest levers remain contributing enough to get the full employer and government money, choosing an appropriate fund, and keeping fees low.
Frequently Asked Questions
How is KiwiSaver growth calculated?
Your balance and each monthly contribution compound at the expected return (annual rate ÷ 12 per month). $15,000 plus $400/month for 20 years at 6% grows to about $234,469, with roughly $123,469 of that being investment growth — before fees, PIE tax, and the government contribution.
Who contributes to my KiwiSaver?
Three sources: you (a chosen percentage of your gross pay — commonly 3%, 4%, 6%, 8%, or 10%), your employer (at least a set minimum percentage on top), and the government (an annual contribution up to a cap if you contribute at least the qualifying minimum). Not contributing enough to capture the employer and government money leaves free money behind.
How does my fund choice affect growth?
A lot. Your fund type — defensive, conservative, balanced, growth, or aggressive — drives long-run returns and volatility. Younger savers with a long horizon often benefit from a growth fund, while those near retirement or a first-home withdrawal may prefer lower volatility. The right fund for your timeline meaningfully changes the outcome.
Are KiwiSaver returns taxed?
Yes — via the PIE (Portfolio Investment Entity) regime at your prescribed investor rate (PIR), which caps the tax on investment income. This simple projection doesn't deduct PIE tax or fund fees, so the real net figure is somewhat lower. Make sure your PIR is set correctly to avoid over- or under-paying.
Can I use KiwiSaver for a first home?
Generally yes — after a qualifying membership period you can withdraw most of your KiwiSaver balance toward buying your first home (leaving a minimum balance), and you may also qualify for a government first-home grant. KiwiSaver thus serves both retirement and first-home goals, which makes early, consistent contributing valuable.
Related Calculators
Methodology & Review
The future value compounds a starting balance and a fixed monthly contribution at the annual return, compounded monthly. It assumes deposits at month end and a constant return; it does not separately model the employer contribution, the annual government contribution, fund fees, or PIE tax on returns.
Written by Ugo Candido · Last updated May 22, 2026.