Mortgage calculator
See what your home loan repayments would be each week, fortnight or month. You can also check the total interest over the term and how much sooner you could pay it off by paying extra.
Most banks let you make some extra payments on a fixed rate loan without charging a break fee.
Fortnightly repayment
$1,594.08
| Total interest over 30 years | $613,381 |
| Total repaid | $1,243,381 |
If the rate rises 2 points to 7.19%, the fortnightly repayment becomes $1,970.84, which is $376.76 more.
Would a lower rate help bring down your fortnightly repayment of $1,594.08?
A licensed mortgage adviser will look at your situation and tell you which rates and loan options you might qualify for. This advice is free.
Your loan year by year
How much of each year's repayments goes on interest and how much pays down the loan.
| Year | Interest | Principal | Left to pay |
|---|---|---|---|
| 1 | $32,475 | $8,971 | $621,029 |
| 2 | $31,998 | $9,448 | $611,581 |
| 3 | $31,495 | $9,951 | $601,630 |
| 4 | $30,965 | $10,481 | $591,149 |
| 5 | $30,408 | $11,038 | $580,111 |
How this calculator works
The calculator works the way banks do for a table loan. Every repayment is the same, and as time goes on, more of each one goes to the principal and less to interest. The calculator splits the annual rate across the repayments in a year, then works out the repayment that pays off the loan by the end of the term.
The result covers principal and interest only, without fees, insurance or rate changes. Most New Zealand home loans are fixed for 1 to 5 years and then refixed, so treat the total interest as an estimate at today's rate.
If you add an extra amount, the calculator puts all of it straight onto the loan. Your bank keeps your regular repayment the same for the whole term, so paying extra means you'll pay off the loan sooner and pay less interest. The table under the ask shows how much interest and principal you pay each year and what you still owe at the end of it. If you're on a fixed rate and pay more than your bank allows, you could be charged a break fee.
The calculator starts with a $630,000 loan, which is about the national median sale price of $784,363 minus a 20% deposit, at 4.95%, the average 1-year special rate at the end of October 2026. You can change these to match your own loan.