New Zealand Compound Interest Calculator
This calculator estimates compound interest growth on NZD savings, term deposits, and KiwiSaver investments. Calculations apply user-defined rate, term, and contribution inputs, with reference rates published by the RBNZ, IRD, and the Sorted (Retirement Commission) framework.
Enter Investment Details
Input the GBP value you want to convert to its inflation-adjusted equivalent.
Select Compounding Frequency
Choose how often interest compounds — Weekly, monthly, quarterly, or annually.
Review the Projection
Each tab shows the breakdown — Summary, Composition, Compare scenarios, and Milestones.
Compound Interest Calculator
Project investment growth — figures shown in NZD
Summary
Investment Summary
An initial investment of $10,000 with $500 contributed monthly at 6.0% annual interest (compounded monthly) grows to $91,940 over 10 years.
Total contributions add up to $70,000, with $21,940 earned in interest — including $2,180 of compound growth (interest earned on previously earned interest).
Growth Projection
Yearly Breakdown
Year-by-year contributions, interest and balance. Figures reflect the view setting (Future $ or Today's $).
| Year | Contributions | Interest | Total Invested | Balance |
|---|
Scenario Comparison
How different choices affect the final balance, all using your selected period and rate.
Compounding Frequency Comparison
Same principal, contribution, rate and period — only the compounding frequency changes.
| Frequency | Final Value | Difference vs Annual |
|---|
Investment Milestones
Estimated time to reach common UK savings and investment milestones, based on the inputs above.
When you'll reach common targets
| Target | Years | Estimated Year |
|---|
New Zealand Investment Options
Common investment types available to New Zealand savers and investors, with typical historical returns and risk levels. Tap any option for detailed considerations.
High-Interest Savings Accounts
Very Low RiskOn-call savings from major NZ banks (ANZ, ASB, BNZ, Westpac, Kiwibank) and challengers (Heartland, Rabobank, Squirrel). Bonus rates often require regular deposits or no withdrawals. Protected up to NZD 100,000 per depositor per licensed deposit taker under the Depositor Compensation Scheme since 1 July 2025.
Advantages
- DCS protected up to NZD 100K
- Instant access to funds
- No market risk
- RWT deducted at source
Considerations
- Bonus rate conditions
- Rates can change
- RWT applies to all interest
- Below RBNZ inflation possible
Term Deposits
Very Low RiskFixed-rate NZD deposits locked for set tenures (30 days to 5 years). PIE term deposits cap tax at 28% PIR (vs RWT up to 39%) — significant for higher earners. DCS protected up to NZD 100,000 per depositor per Scheme member.
Advantages
- Locked-in rate for term
- DCS protected up to NZD 100K
- PIE versions cap tax at 28%
- Predictable returns
Considerations
- Funds locked for tenure
- Early break penalties (often base rate)
- Miss future rate rises
- Minimum deposit thresholds
NZ Government Bonds & Kiwi Bonds
Low–Medium RiskNZ Government Bonds (NZGBs) and Kiwi Bonds issued by NZ Debt Management. Kiwi Bonds available direct to individuals from NZD 1,000 (six-month, 1, 2, 4-year terms). NZGBs traded on NZX Debt Market. Backed by the Crown — minimal credit risk.
Advantages
- Crown-backed (no default risk)
- Predictable income stream
- Lower volatility than equities
- Portfolio diversification
Considerations
- Interest rate risk on capital
- RWT on interest payments
- Lower long-term returns vs equities
- NZGB minimum NZD 10,000
KiwiSaver (Conservative)
Low–Medium RiskCapital-preservation KiwiSaver fund, mostly bonds and cash. Suitable for those approaching age 65 or with low risk tolerance. Locked until age 65 (with first-home and hardship withdrawal exceptions). Government contribution NZD 260.72/year max (since 1 July 2025).
Advantages
- Government contribution NZD 260.72
- Employer contribution 3.5%+ from Apr 2026
- PIE tax cap at 28%
- First home withdrawal eligible
Considerations
- Locked until age 65
- Lower long-term growth
- May not beat NZ inflation
- Income earners over $180K excluded from govt contribution
Gold & Precious Metals
Medium RiskPhysical gold from NZ Mint or bullion dealers, ASX-listed gold ETFs (PMGOLD, GOLD), or US gold ETFs via Sharesies/Hatch/Tiger. Investment-grade gold is GST-zero-rated in New Zealand. Traditional inflation hedge priced in USD.
Advantages
- Inflation hedge
- Investment-grade gold zero-rated GST
- Safe-haven asset
- Portfolio diversification
Considerations
- No income / dividends
- Storage costs (physical)
- USD/NZD currency risk
- Price volatility
KiwiSaver (Balanced)
Medium RiskThe most popular KiwiSaver default — roughly 60% growth (shares, listed property), 40% income (bonds, cash). Professional management with moderate risk-return balance. Many providers including Booster, Generate, Milford, Simplicity, Kiwi Wealth, ANZ, ASB, Westpac, BNZ.
Advantages
- Government contribution NZD 260.72
- Employer 3.5%+ contribution (Apr 2026)
- Built-in diversification
- PIE tax cap at 28%
Considerations
- Locked until age 65
- Management fees apply
- Market volatility exposure
- Total Remuneration package risk
ETFs (NZX-listed)
Medium–High RiskNZX-listed ETFs from Smartshares (NZ Top 50, Total World, US 500, S&P/NZX 50, etc.) and Kernel Wealth (Global 100, NZ 50). Most are PIE-taxed. Low expense ratios from 0.20%. Trade via Sharesies, Hatch, ASB Securities, Direct Broking, Jarden Direct.
Advantages
- PIE tax cap at 28%
- Imputation credits on NZ shares
- Low expense ratios
- Instant diversification
Considerations
- Market risk exposure
- Brokerage/platform fees
- FIF rules on direct foreign holdings >NZD 50K cost
- Currency risk on global ETFs
NZ Property (Direct)
Medium–High RiskResidential or commercial property. Bright-line test of 2 years applies to residential property sold on or after 1 July 2024 (gains taxable if sold within window unless main-home exclusion applies). LVR rules apply for investment lending. KiwiSaver first-home withdrawal available after 3 years.
Advantages
- Leverage amplifies gains
- Tangible asset
- Rental income stream
- KiwiSaver first-home withdrawal
Considerations
- Bright-line test 2 years
- LVR limits on investor lending
- Interest deductibility (residential)
- Maintenance & tenancy costs
Listed Property (NZX-PIE)
Medium–High RiskNZX-listed property entities including Kiwi Property, Goodman Property, Precinct, Argosy, Stride and Vital Healthcare. Most are PIE-structured for tax efficiency. Access commercial, industrial, retail and healthcare property without direct ownership burdens.
Advantages
- PIE-structured tax efficiency
- Liquid (NZX traded)
- Quarterly distributions
- Professional asset management
Considerations
- Share-price volatility
- Interest rate sensitive
- Sector concentration risk
- Management fees embedded
KiwiSaver (Growth)
Medium–High RiskGrowth-focused KiwiSaver — roughly 80% shares (NZ + global), 20% bonds and cash. Suited to younger investors with 10+ years until age 65. Higher long-term growth potential but greater short-term volatility. Aggressive funds available with 95–100% growth assets.
Advantages
- Government contribution NZD 260.72
- Employer 3.5%+ contribution
- Higher long-term growth potential
- PIE tax cap at 28%
Considerations
- Locked until age 65
- Higher short-term volatility
- Sequence-of-returns risk near 65
- Market downturn exposure
NZX Direct Shares
High RiskDirect NZX-listed shares including Fisher & Paykel Healthcare, Auckland International Airport, Mercury, Meridian, Spark, Mainfreight, a2 Milk, Air NZ. NZX 50 long-term ≈ 9–10% p.a. with dividends. Imputation credits boost after-tax returns for NZ residents.
Advantages
- Imputation credits attached
- Dividend income stream
- No bright-line test on shares
- Direct ownership
Considerations
- Single-stock volatility
- Capital can be lost
- Smaller market than ASX/NYSE
- RWT applied to dividends
Cryptocurrency
Very High RiskDigital assets via NZ-based exchanges including Easy Crypto, Independent Reserve, Kiwi-Coin and Swyftx NZ. IRD treats crypto as property — gains are generally taxable if acquired with intent to sell. Different from most other NZ investments where capital gains are tax-free.
Advantages
- 24/7 global market
- Portfolio diversification
- Staking yields (some)
- NZ-based exchanges available
Considerations
- Extreme volatility
- Can lose 50%+ quickly
- IRD treats as property — taxable
- Security & scam risks
Frequently Asked Questions
Common questions about compound interest, ISAs, pensions and tax in the UK. Answers reference HMRC, FCA, Bank of England and FSCS official guidance.
Important Disclaimer
For educational and informational purposes only. This calculator produces estimates based on the inputs provided and assumes a constant compounding rate over the projection period. Figures referenced reflect New Zealand rates and rules current to May 2026: RBNZ Official Cash Rate 2.25% (held April 2026), RBNZ inflation target 1–3% (midpoint 2%), KiwiSaver minimum employee & employer contributions rising from 3% to 3.5% from 1 April 2026 (further rise to 4% scheduled for 1 April 2028), Government KiwiSaver contribution NZD 260.72 maximum per year (since 1 July 2025), PIE Prescribed Investor Rate (PIR) capped at 28%, RWT rates 10.5%, 17.5%, 30%, 33% or 39% (45% without IRD number), and the Bright-line Test 2 years for residential property sold on or after 1 July 2024. NZ Superannuation eligibility age remains 65; NZ Super single-living-alone rate ≈ NZD 1,110/fortnight (M code, 1 April 2026 rates). Past investment performance is not a reliable indicator of future returns.
No warranty of accuracy. While Money Snap takes reasonable care to source figures from official authorities (RBNZ, IRD, FMA, MBIE, Sorted/Retirement Commission, Work and Income), this calculator is provided "as is" without any express or implied warranty as to accuracy, completeness, timeliness, or fitness for any particular purpose. The OCR is reviewed by RBNZ several times a year, KiwiSaver contribution rules change with each Budget cycle, tax thresholds and PIR/RWT rates change at IRD discretion, and bright-line and FIF rules are revised periodically — figures shown may be out of date following Monetary Policy Committee decisions, IRD updates, or legislative change. Individual circumstances including tax residency, total income, KiwiSaver scheme rules, employer agreements (including Total Remuneration packages), and other tax obligations may materially affect actual outcomes.
Not financial advice. Money Snap is not licensed by the Financial Markets Authority (FMA) and does not hold any Financial Advice Provider (FAP) licence under the Financial Markets Conduct Act 2013. Information provided is general in nature only and does not take into account your personal circumstances, financial situation, goals, or objectives. Results do not constitute regulated financial advice, investment advice, KiwiSaver advice, tax advice, or insurance advice, and use of this calculator does not create an advisory relationship. Before acting on any figure shown, obtain personal advice from a licensed Financial Advice Provider (search the FSPR Financial Service Providers Register), or seek free guidance from Sorted (Te Ara Ahunga Ora — Retirement Commission). Tax queries can be directed to IRD, and KiwiSaver queries to your scheme provider.
Limitation of liability. To the maximum extent permitted by law, Money Snap accepts no liability for any loss, damage, cost, or expense — direct or indirect — arising from reliance on this calculator or the information it produces. Investment products (KiwiSaver funds, NZX-listed shares, ETFs, listed property, managed funds, cryptocurrency) carry capital risk and may fall as well as rise in value. The Depositor Compensation Scheme (DCS) protects eligible NZD deposits up to NZD 100,000 per depositor per licensed deposit taker (effective 1 July 2025). DCS coverage applies only where a licensed deposit taker fails — it does not cover investment losses from market movements, KiwiSaver, managed funds, foreign-currency deposits, or losses through scams or fraud. Users are responsible for verifying all figures with the relevant authority before relying on them. Use of this calculator is subject to our Terms of Use.
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