Time to First $100,000 Calculator

How this calculator works

The calculator uses the standard formula for a lump sum plus regular contributions compounding at a fixed monthly rate. Your current balance grows on its own at the chosen rate, and each month's new contribution starts compounding from the moment it goes in. Because later contributions have less time to grow than earlier ones, the maths cannot simply be reversed with basic arithmetic. Instead, the calculator solves for the number of months, algebraically, at which your starting balance plus all contributions and all accumulated growth first equals $100,000. It then converts that number of months into a more readable years-and-months figure and works out an approximate target date based on today. None of this changes what is actually happening to your money, it simply answers the question "when" in a precise way rather than a rough guess.

Why the first $100,000 feels slow

In the early years of any savings plan, your contributions are doing almost all of the work, because there simply is not much money invested yet for a percentage return to act on. A 4.5% annual return on a $10,000 balance is only $450 for the year, a small amount next to a typical worker's own contributions. But the same 4.5% return on a $90,000 balance is $4,050, roughly nine times as much, without the saver doing anything differently. This is the practical reason many people notice their second $100,000 arrives faster than their first, even with identical contributions and the same return: the base the return is acting on has grown much larger. It is not a trick or a change in the rules, it is simply how percentage growth behaves on compounding sums, and it is also why the growth share shown in your result climbs the longer your money has to compound.

Worked example

Say you already have $10,000 saved, contribute $600 a month between your own KiwiSaver contribution and your employer's matching contribution, and your fund is invested in a Growth option assumed to return 4.5% a year, net of fees and tax. Solving the compounding formula for this balance and contribution shows it takes just over 113.5 months, which rounds to 9 years and 6 months, to reach $100,000. Over that period you will have contributed $68,108.70 of your own and your employer's money (600 multiplied by 113.5 months), on top of the $10,000 you started with, for total money in of $78,108.70. The remaining $21,891.30 is investment growth, meaning almost 22 cents of every dollar in your first $100,000 came from the market rather than your own pocket. Compare that to putting the same $600 a month under the mattress with no investment return at all: reaching $100,000 that way from a $10,000 base would take exactly 150 months, or 12 years and 6 months, since with no growth the maths is simple division. In other words, investing rather than simply saving cuts roughly 3 years off the time to your first $100,000, using identical contributions.

A second example shows the effect over a longer run. Starting from $0 and contributing $300 a month into a Balanced fund assumed to return 3.5% a year, it takes about 19 years and 5 months to reach $100,000. Of that total, $69,958.38 is your own contributions and $30,041.62, just over 30%, is investment growth. Doing the same with no investment return would take 27 years and 9 months, 8 years and 4 months longer, illustrating how the time compounding saves you keeps growing the longer your money is invested.

What counts as your monthly contribution

Enter whatever actually lands in the account each month. For a KiwiSaver saver in paid employment, that is usually your own contribution, commonly 3.5% of gross pay at the default rate from 1 April 2026 (rising to 4% from 1 April 2028), plus your employer's matching contribution at the same rate on your gross pay, since employer KiwiSaver contributions are compulsory once you are contributing. If you are eligible for the government's annual KiwiSaver contribution, currently a maximum of $260.72 a year for anyone contributing at least $1,042.86 of their own money in the KiwiSaver year, you can add roughly $21.73 a month to your figure to reflect it, though it is technically paid once a year rather than monthly. Self-employed savers with no employer contribution should enter only their own voluntary payments. If your income is above $180,000, the government contribution no longer applies, so leave it out.

What this calculator assumes

• A constant monthly contribution and a constant annual return for the entire period. Real pay rises, contribution rate changes and fund switches are not modelled.
• Monthly compounding, applied evenly across the year, rather than the exact daily unit pricing and fee timing your actual KiwiSaver or investment provider uses.
• The Conservative, Balanced, Growth and Aggressive presets are the Financial Markets Authority's standard long-run projection assumptions, net of fees and after the top 28% prescribed investor rate. They are a planning reference, not a promise of what any specific fund will return in future.
• Results are a single milestone estimate ($100,000), not a full retirement or long-term projection, and do not account for withdrawals, fund switches, or a first-home withdrawal part-way through.
• Figures are rounded for display and are indicative only.

Who this calculator is for

This is for anyone tracking towards their first $100,000 in KiwiSaver, a managed fund, or any other regular savings plan, and wanting a realistic sense of when they will get there rather than a vague guess. It suits younger savers early in their working life mapping out a long first milestone, anyone who has recently increased their contribution rate or switched funds and wants to see the new timeline, and savers who want to understand, in concrete years and months, how much of their result will come from their own money versus investment growth. If you want to see your account balance projected right through to retirement rather than to a single $100,000 marker, our KiwiSaver Retirement Projection Calculator models that fuller, longer-horizon picture.

Frequently Asked Questions

How long does it take to save your first $100,000?

It depends on your starting balance, monthly contribution and return. Starting from $10,000 with $600 a month in a Growth fund at 4.5%, it takes about 9 years and 6 months. Starting from zero with $300 a month in a Balanced fund at 3.5%, it takes about 19 years and 5 months. Enter your own figures above for your personal timeline.

Why is the first $100,000 considered the hardest?

Early on, almost all of your balance growth comes from your own contributions, since there is not yet enough invested for compounding returns to add much in dollar terms. Past roughly $100,000, the same percentage return produces a larger dollar amount each year, so growth speeds up even on identical contributions, which is why the second $100,000 often arrives faster than the first.

What return rate should I use?

The calculator offers four Financial Markets Authority standard KiwiSaver projection assumptions, net of fees and after the top 28% prescribed investor rate: Conservative 2.5%, Balanced 3.5%, Growth 4.5% and Aggressive 5.5%. These are the same figures KiwiSaver providers use in your annual statement projections. A custom rate option is also available.

Does this include KiwiSaver employer and government contributions?

Only if you include them in your monthly figure. A realistic employee figure is your own contribution (commonly 3.5% of gross pay from 1 April 2026) plus your employer's matching 3.5%. The $260.72 annual maximum government contribution, if you qualify, averages about $21.73 a month.

What is the difference between contributions and growth in the result?

Contributions are the money you and, where relevant, your employer put in. Growth is the difference between your starting balance plus contributions and the final $100,000, meaning the investment return generated along the way, net of the fund's assumed fees and tax.

Does compounding really make that much difference?

Yes, and more so over longer periods. The calculator shows how long the same contributions would take at a 0% return, with no investment growth at all, so you can see the years compounding actually saves you. On a roughly 10-year plan this can be 2 to 3 years; on a 20-year plan it can exceed 8 years.

Is this the same as a full KiwiSaver retirement projection?

No, it answers one specific question, time to a single $100,000 milestone, with a constant contribution and return. Our KiwiSaver Retirement Projection Calculator models the fuller picture through to retirement, including changing contributions and fund switches.

What if my monthly contribution or return changes over time?

The calculator assumes both stay constant, to keep the milestone answer clear and explainable. Re-run it whenever your circumstances change meaningfully, such as after a pay rise, a KiwiSaver contribution rate change, or a fund switch, to get an updated estimate.

Related calculators

• KiwiSaver Retirement Projection Calculator: a full year-by-year projection of your KiwiSaver balance through to retirement age.
• Retirement Number Calculator: work out the total nest egg you need for your target retirement income.
• Compound Interest Calculator: project how any lump sum and regular contribution grows over a chosen number of years.
• Savings Goal Calculator: work backwards from a target amount to the monthly saving required.
• Rule of 72 Calculator: a quick rule of thumb for how many years it takes any lump sum to double at a given return.

Official NZ sources

This calculator is built from primary New Zealand sources. Always confirm current figures against the official source for your situation:

• Financial Markets Authority (FMA): standard KiwiSaver return, fee and tax assumptions for projections
• Inland Revenue (IRD): KiwiSaver contribution rates and government contribution rules
• Sorted (Te Ara Ahunga Ora, Retirement Commission): KiwiSaver fund comparison tool