Managed Fund Return Calculator NZ
This calculator projects how a New Zealand managed fund or ETF grows over time once you strip out the management fee and PIE tax, so you can judge an investment on what you would actually keep rather than its advertised return. You enter your starting balance, a regular monthly contribution, the expected annual return, the fund's annual management fee, your Prescribed Investor Rate (PIR) and the number of years you plan to invest. The calculator grows your balance month by month at the return less the fee, adds your contribution each month, and deducts PIE tax from the net growth every year, the way most managed funds and KiwiSaver-style PIE funds work in practice. It returns your projected final balance after fees and tax, alongside a breakdown of how much came from your own contributions and how much came from net growth after costs. This makes it easy to see how much a fee and your PIR quietly erode a return over decades, since even a small fee compounds against you every year. Use it to compare funds with different fee structures, test how your PIR changes the outcome, or see whether a bigger contribution or a longer timeframe makes the greater difference. It is a simplified model; real returns fluctuate and are never guaranteed, so treat the result as an indicative estimate for planning, not financial advice.
Applies the return less the fee, then taxes the net growth at your PIR each year, with monthly contributions. A simplified model; real funds vary and returns are not guaranteed. Estimate only, not financial advice.
How it works
The calculator grows your balance month by month at the return less the management fee, adds your monthly contribution, and reduces the net growth each year by your PIR tax. This captures the two biggest drags on a long-run result: the fee, which compounds against you every year, and PIE tax at up to 28%. The final balance is the after-cost figure that actually matters.
Worked example
$10,000 plus $300 a month for 20 years at a 6% return, less a 0.8% fee and 28% PIR, grows to roughly $128,000. You contribute about $82,000 of that, with the rest from net growth, after fees and tax have taken their share.
Related calculators
- KiwiSaver Fee Calculator: fee impact.
- Compound Interest (PIE) Calculator: PIE vs non-PIE.
- Managed Fund vs KiwiSaver: compare.
- Investment Calculator: investing growth.
- Understanding Managed Fund Fees: background on this topic.