Interest Only Mortgage Calculator NZ 2026
An interest-only mortgage calculator is a valuable tool for borrowers looking to understand their repayment obligations when opting for an interest-only home loan. Unlike a traditional mortgage, where each payment includes both principal and interest, an interest-only loan requires you to pay only the interest on the loan for a set period. This means your repayments will be significantly lower during the interest-only phase, giving you greater flexibility in managing your cash flow. This calculator allows you to determine exactly how much you will need to pay during the interest-only period based on your loan principal and interest rate. It provides detailed payment breakdowns across different repayment frequencies, including monthly, fortnightly, and weekly interest-only payments. Whether you are a first-time homebuyer, an investor looking to maximise cash flow, or someone refinancing an existing loan, this tool helps you assess the affordability of an interest-only mortgage. Interest-only home loans are often used by property investors or homeowners who plan to sell or refinance before the principal repayments begin. However, it is important to understand that once the interest-only period ends, your repayments will increase as you start paying down the principal. Using this calculator, you can compare different loan scenarios, estimate your ongoing costs, and make informed financial decisions before committing to an interest-only mortgage. To get started, simply enter your loan amount and interest rate, and the calculator will instantly generate your estimated repayments. Explore your options today and gain a clear understanding of how an interest-only mortgage could fit into your financial plan.
Enter your information into the calculator below.
Loan principal amount
Interest rate (in percent; i.e. 4.5)
Interest payment amount per month
Interest payment amount per fortnight
Interest payment amount per week