Free KiwiSaver Contribution Comparison Calculator for New Zealanders
Bumping your contribution rate from 3.5% to 4% sounds small. Compounded over 30 years the difference can be tens of thousands of dollars. The calculator projects each option side by side.
Your contribution
Based on a $80,000 salary, 3.5% employee + 3.5% employer over 30 years.
About our KiwiSaver Contribution Comparison Calculator
The contribution-rate decision is one of KiwiSaverKiwiSaverNZ workplace retirement savings scheme. From 1 April 2026, minimum employee and employer contributions are both 3.5% of gross pay (rising to 4% in 2028); the government adds 25c per $1, capped at $260.72/yr.View in glossary →’s biggest long-run levers. From 1 April 2026 the minimum is 3.5% (rising to 4% on 1 April 2028). Above that, the available rates are 4%, 6%, 8%, and 10%. Most NZ employees stay on the minimum because the per-pay difference looks small.
The calculator shows what that small difference compounds into. On a $80,000 salary over 30 years at 5.5% return, the gap between 3.5% and 6% comes to about $145,000 of extra balance at 65, on a per-fortnight cost difference of $77.
Move the contribution-rate slider to compare your current rate against alternatives. Move the years-to-retirement slider to see how a longer or shorter horizon changes the balance impact.
How to use it
Enter your salary, your current KiwiSaver contribution rate, your target rate, and the years to retirement. Set the expected return; 5.5% is a long-run balanced-fund average, 7% is a typical growth fund, 4% is a conservative fund.
The result panel returns the balance at retirement under each rate and the dollar gap between them. Both projections include the matching employer contribution (capped at the minimum 3.5%) and the $260.72/year government contribution.
Why use it
Most NZ households consider only the per-fortnight cost of a higher rate, not the long-run balance. The calculator surfaces both numbers so the trade-off is concrete: $X a fortnight extra now for $Y of extra balance at 65.
For people in their 20s and 30s, the time horizon means small rate differences compound substantially. For people in their 50s, the horizon shrinks and the per-fortnight cost matters more relative to the eventual balance impact. The calculator handles both cases by varying the years-to-retirement input.
The maths behind it
FV = M × ((1+r)n − 1) ÷ r where M is annual employee + employer contributions Annual employee contribution is salary times the rate (3.5%, 4%, 6%, 8%, or 10%). The employer adds the matching minimum (3.5% from 1 April 2026, rising to 4% from 1 April 2028). The combined annual figure compounds at the assumed return rate over the years to retirement. The maths is the standard future-value-of-an-annuity formula. The calculator uses end-of-year contribution timing.
Worked example
Aaron, accountant in Te Anau, comparing 3.5% and 6% contribution rates over 30 years on a $94,000 salary.
Aaron is 35 with no current KiwiSaver balance, earning $94,000. He is debating whether to stay on the 3.5% minimum or push his contribution rate to 6%.
At 3.5%: $3,290 annually from him + $3,290 from employer = $6,580 total. Over 30 years at 5.5%, this compounds to roughly $471,000.
At 6%: $5,640 from him + $3,290 from employer = $8,930 total. Same horizon and return rate: about $640,000, $169,000 more than the 3.5% scenario.
Net cost to Aaron of the higher rate: $2,350 a year, or $90 a fortnight after tax (since employee KS comes out of after-tax pay). The trade-off is $90 a fortnight for 30 years against $169,000 of extra balance at 65.
Things to keep in mind
- Employer match has a floor. The minimum employer match is 3.5% from 1 April 2026 and 4% from 1 April 2028. If you contribute more than the minimum (4%, 6%, 8%, 10%), the employer is not obligated to match the higher rate; most employers stick to the minimum.
- Returns compound exponentially, contributions are linear. Doubling the contribution rate roughly doubles the retirement balance over a long horizon. Doubling the return rate more than doubles the balance because returns earn returns. This is why fund choice and fee level often matter more than contribution rate over 20+ year horizons.
- Salary growth is not modelled. The calculator assumes a flat salary in nominal terms. In practice, salaries usually rise faster than inflation in early career and slower later. The projection therefore tends to understate the eventual balance for younger contributors.
- Contribution rate changes are easy. Employees can change their KiwiSaver contribution rate at any time by notifying their employer. The change takes effect on the next pay run. There is no penalty for stepping up, stepping down, or pausing.
- Government contribution maxes at $260.72/year. The government adds 25c per dollar of member contribution, capped at $260.72 a year (reached at $1,042.86 of member contributions). Above that figure, no additional government top-up. The calculator assumes the maximum is met for any contribution rate above 1.5%.
NZ-specific notes
FAQs
How much extra does a higher contribution rate cost me each fortnight?
The increase comes from after-tax pay. Stepping from 3.5% to 4% on a $80,000 salary costs $400 a year, or $15 a fortnight. From 4% to 6% costs $1,600 a year, or $62 a fortnight. From 3.5% to 10% costs $5,200 a year, or $200 a fortnight. The take-home pay calculator shows the per-pay impact.
Why does the employer match stop at 3.5%?
The 3.5% (rising to 4%) is the legal minimum. Most NZ employers stick to that figure rather than match higher employee contributions. Some larger employers do offer to match up to 6% or 8% as a benefit; check your employment agreement.
Should I contribute more than the minimum?
The calculator shows the long-run effect; it does not advise either way. Compounding favours higher contributions over long horizons, but the right rate depends on income, other savings goals, and short-term obligations. Sorted’s impartial guidance can help with the trade-off.
Can I change my rate later?
Yes, anytime. Notify your employer (one-line email or formal request, depending on payroll system) and the change takes effect on the next pay run. There is no minimum stay-period and no penalty for stepping down later.
What if I take a savings suspension?
A savings suspension pauses both employee and employer contributions for 3-12 months, available after at least 12 months of contributions. The calculator does not model suspensions; the effect is roughly proportional to the missed months relative to the total period.
Does the calculator account for tax?
Employee contributions come from after-tax pay (no further tax). Employer contributions are subject to ESCT before they enter the fund. Returns inside the fund are taxed at your PIR (10.5%, 17.5%, or 28%). The published fund returns used as the calculator’s default usually reflect after-PIE-tax figures.
References & sources
- Inland Revenue, "KiwiSaver changes (April 2026 contribution rates)". ird.govt.nz
- Inland Revenue, "Government contribution to KiwiSaver". ird.govt.nz
- Financial Markets Authority, "KiwiSaver annual report". fma.govt.nz
- Te Ara Ahunga Ora Retirement Commission, "Sorted goal planner and fund finder". sorted.org.nz