Term Deposit Calculator NZ — Interest After RWT and Inflation

See what an NZ term deposit really pays: gross interest, resident withholding tax (RWT) at your rate, net interest, the value at maturity, and the real return after inflation. Compare "interest at maturity" with compounding options.

Use the advertised rate for your term and amount.

Resident withholding tax is deducted by the bank at the rate you elect; choose the one matching your total income.

Gross interest—
RWT deducted—
Net interest—
Value at maturity (net)—
Net return p.a.—
Real return p.a. after inflation—

General information only — not financial, tax or legal advice. Figures are estimates from the inputs you enter. Confirm with your adviser, accountant, lender or insurer.

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Gross vs net — the number banks don't headline

The advertised rate is before tax. Banks deduct resident withholding tax at the rate you nominate (it should match your income tax rate), so a 4.5% deposit is worth about 3.0% to someone on the 33% rate. Then inflation takes its cut. That's why a term deposit is capital-safe but not always wealth-building — run the real-return line before you lock money away for two or three years.

Interest at maturity vs compounding

Shorter deposits usually pay interest at maturity; longer ones often let you take interest monthly or quarterly, or compound it. Compounding helps a little over one year and more over several. If you're comparing banks, compare the net figure over the same term — and remember that breaking a term deposit early usually costs you most of the interest.

Assumptions and sources

Interest Simple interest for 'at maturity'; otherwise compound at the selected frequency for the term.
RWT Deducted from gross interest at the elected rate (10.5/17.5/30/33/39%; 45% no-declaration) — ird.govt.nz/rwt
Real return (1 + net rate) ÷ (1 + inflation) − 1; inflation is your assumption, not a forecast.
Not included Break fees, PIE fund tax treatment, bonus-rate conditions.

Last reviewed 6 September 2026. Rates and thresholds change — check the linked sources before relying on a figure.

Frequently asked questions

Which NZ bank has the highest term deposit rates?

Rates change weekly and differ by term and amount. Compare on interest.co.nz or the banks' own pages, then run the net figure here — a slightly higher rate at a bank that only pays at maturity can lose to a compounding option elsewhere.

How much interest will $100,000 earn in a year?

At 4.5% paid at maturity, $4,500 gross; after RWT at 33% that is $3,015, or about $58 a week. Change the amount and rate above for your own figures.

Do I pay tax on term deposit interest in NZ?

Yes — the bank deducts resident withholding tax before paying you. If you have not given the bank your IRD number, RWT is deducted at 45%. Interest still counts toward your total income for the year.

What is a good term deposit rate in NZ right now?

It depends on the OCR and how far you fix. Rather than chasing the top rate, check the net return after RWT and inflation, and keep an emergency fund in an on-call account so you never have to break a term deposit early.