Loan Comparison Calculator NZ 2026
This calculator puts two loan offers side by side so you can see which one actually costs less over its full life, not just which has the lower headline rate. Name each loan and enter the loan amount, annual interest rate, loan term in years, payment frequency (monthly, fortnightly or weekly), any upfront fees such as application, valuation or legal costs, and any ongoing annual fee. It runs a full amortisation on both loans and returns a winner banner showing which is better value and the total dollar saving over the term. Below that sit matched result cards showing the repayment per period, total interest, total fees, and the all-in total cost for each loan, plus a visual bar comparison and a year-by-year table tracking each loan's balance, yearly interest, and the running interest saving between the two. Use it to weigh up competing bank offers, test whether a higher rate with no fees beats a lower rate loaded with charges, compare a 25-year term against a 30-year term, or see the real cost difference between fixing your rate and staying on floating. A small rate gap compounds into a large sum over 20 or 30 years, so run the actual numbers rather than judge by rate alone. Figures are indicative estimates only and not financial advice; confirm exact terms, fees and rates with your lender before committing.
| Year | A balance | A interest | B balance | B interest | Int. saving |
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What to compare when choosing a loan
The interest rate gets most of the attention, but the total cost is what matters. A loan with a slightly higher rate and no fees can be cheaper overall than a low-rate loan with significant upfront and ongoing fees. This calculator adds every cost together so the comparison is genuinely fair: repayments, interest, application fees, valuation costs, and annual package fees.
A real example: 0.4% rate difference on a $500,000 mortgage
At 6.49% vs 6.89% on a $500,000 30-year fortnightly loan, the total interest difference is approximately $48,000. If the lower-rate bank charges a $500 application fee and $250 annual package fee, that adds $8,000 over 30 years, bringing the net saving to about $40,000. That is still a very large sum, and it shows why even small rate differences justify careful comparison before signing.
Comparing different loan terms
Enter the same loan at 30 years in column A and 25 years in column B to see the trade-off between lower repayments and less total interest. Reducing a $500,000 loan from 30 to 25 years at 6.5% typically saves around $125,000 in interest. The extra fortnightly repayment is usually $85-$120. If you can afford it, the shorter term almost always wins on total cost.
Fixed versus floating rates
Enter your current fixed rate in column A and the floating rate in column B. A fixed rate provides certainty against rises. Most NZ borrowers fix for 1 to 3 years then refix based on conditions. Use this calculator to see the exact dollar impact of each choice at today's rates.