Credit Card vs Debit Card Cost Calculator NZ

This calculator compares the yearly cost of running a credit card against a low-cost debit card in New Zealand, so you can see which actually suits the way you spend. Credit cards are often sold on their rewards and perks, but those come with an annual or monthly fee and, crucially, interest on any balance you do not clear in full each month. A debit card spends your own money, so it charges no interest and usually little or no fee, but it earns few rewards. The right choice depends entirely on your habits. You enter the credit card's annual fee, the average balance you typically carry from month to month, the card's interest rate, the rewards or cashback you earn in a year, and any debit card fee. The calculator works out the credit card's net annual cost as the fee plus interest on the carried balance, less the rewards, and compares it with the debit card's cost. If you always pay in full, the carried balance is zero and rewards can make the card cheaper or even profitable; if you carry a balance, interest usually swamps the rewards and the debit card wins. Enter your figures to see which card costs you less over a year.

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Debit card is cheaper by $160
over a year
Credit card net cost$160
Debit card cost$0

Credit cost = annual fee + interest on the carried balance, less rewards. A negative credit cost means rewards outweigh the costs. Estimate only.

How it works

The credit card net cost is the annual fee plus interest on the average balance you carry across the year, minus the rewards you earn. The debit card cost is just its annual fee. The calculator compares the two and names the cheaper option and the yearly difference.

Worked example

An 80 dollar fee card carrying a 1,000 dollar balance at 19.95 percent costs 80 plus 199.50 in interest, less 120 in rewards, a net 159.50 dollars that rounds to 160. A free debit card costs nothing, so it is cheaper by 160 dollars a year for this user.

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