Glossary
Interest (declining balance)
The cost of borrowing, charged as a percentage of what you still owe. On a declining-balance loan, interest is calculated on the shrinking balance, not the original amount.
By Leverage Finance · Updated 17 July 2026
Nearly all NZ car loans charge interest on the declining balance: each period, interest is calculated on whatever principal is still outstanding. As your balance falls, the dollar amount of interest in each payment falls with it, and more of each payment goes to the principal.
This is why the pricing on a loan compounds in your favour when it improves. A loan priced even 1% lower charges less interest every single period for the rest of the term, and the longer you have left, the more periods that saving repeats over.
Our guide How car loan interest works covers the mechanics, and the calculator shows the arithmetic on your own numbers.
Same car. See what a better loan looks like.
Two minutes, one soft check to start, no obligation. Your file goes to a panel of NZ lenders and the strongest offer comes back.
Free to check
Keep reading