This calculator shows New Zealand homeowners how much they can save simply by changing how often they pay their mortgage, switching from monthly to fortnightly or weekly repayments. Because more frequent payments mean you pay slightly more across a year and reduce the principal sooner, the interest savings over a full loan term can be substantial. You enter your loan details, and the tool compares the total interest and loan term under each repayment frequency. The breakdown shows the interest paid and payoff date for monthly, fortnightly, and weekly options side by side, revealing one of the simplest and most effective ways to pay a mortgage off faster without finding large extra sums.
| Frequency | Each payment | Total interest | Payoff time |
|---|
Accelerated fortnightly and weekly use half and a quarter of the monthly payment, so you make the equivalent of 13 monthly payments a year instead of 12. Check your lender allows this without simply spreading the monthly amount. Estimate only, on a table loan, not financial advice.
The calculator finds the standard monthly repayment on your loan, then models paying half that amount every fortnight and a quarter every week. Because there are 26 fortnights and 52 weeks in a year, those add up to 13 monthly payments worth a year rather than 12. That extra payment goes straight onto the principal, so interest is charged on a smaller balance and the loan clears sooner, saving interest overall.
A $600,000 loan over 30 years at 6.5% costs about $3,792 a month. Paying $1,896 every fortnight instead adds roughly one extra monthly payment a year, clearing the loan around four to five years early and saving tens of thousands in interest, all without a large lift in outgoings.
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