A Moneybren tool

NZ TERM DEPOSIT CALCULATOR

The rate on the bank’s poster is before tax. This calculator shows New Zealand term deposit returns honestly — the gross interest, the tax (RWT), and what actually lands in your account.

Your deposit

$
% pa
Always shop around — even the big banks like ANZ, ASB, BNZ, Westpac and Kiwibank can have highly varying term deposit rates. This rate is an example.
months
Compounding = interest reinvested into the deposit after tax.
Resident withholding tax — pick the rate matching your income bracket.
At maturity you get back
$0
Gross interest$0
Tax (RWT)$0
Interest you keep$0
After-tax return0%

The same deposit as a PIE

PIE term deposits are taxed at your PIR — capped at 28% — instead of RWT

Payment-by-payment detail

Interest paymentGross interestRWT deductedNet creditedBalance
The fine print, honestly. RWT comes off every interest payment before you see it — the bank handles it automatically, but it means a 4.50% deposit at 33% RWT really pays about 3.02%. If you’re on the wrong RWT rate with your bank, IRD squares it up at year end. Not modelled: early-withdrawal penalties (banks can reduce the rate or refuse), inflation quietly eating the real return, or the exact PIR thresholds — your PIR depends on your income in the last two tax years, so confirm yours with IRD’s PIR finder before switching. Compare the after-tax return here with your mortgage rate before locking money away — repaying debt is a tax-free return.

How to use this calculator

Enter your deposit, the advertised rate, the term, how interest is paid, and your RWT rate. The calculator shows every interest payment with the tax taken off, and the after-tax return you’re really earning.

Try switching between “at maturity” and compounding options — for terms over a year, compounding after tax earns slightly more. And try the PIE comparison with your bank if you’re on 33% or 39%.

Term deposit rates in New Zealand vary more than most people expect — between banks, between terms, and even week to week. A quick comparison across ANZ, ASB, BNZ, Westpac, Kiwibank and the smaller banks before you lock in can be worth real money on a large deposit.

This is a tool only, and none of the information it produces is financial advice. Its accuracy is not guaranteed. Always check your own figures and get advice from your own financial professionals before making decisions.