Home loan repayment calculator

How are home loan repayments calculated?

Most Australian home loans are principal-and-interest loans. Each repayment covers the interest charged for that period, and the rest reduces the amount you owe (the principal). At the start of the loan, interest makes up a larger share of each repayment; over time, more of each payment goes toward paying down the loan.

This calculator uses the standard amortisation formula for a principal-and-interest loan, based on the loan amount, interest rate, loan term and repayment frequency you enter. The how it works page explains our other estimates in more detail.

What happens when interest rates change?

A higher interest rate generally means a higher required repayment, and more interest paid over the life of the loan. A lower rate does the opposite. If your loan has a variable rate, your repayments can move whenever your lender changes its rates.

The "What if the interest rate rises?" table above compares your current assumed rate with rates 1% and 2% higher, so you can see how a rise would change the repayment in this scenario. It is a comparison of scenarios, not a prediction of future interest rates.

Does repayment frequency matter?

Yes, in two ways. The frequency you choose changes how much you pay at each interval — a fortnightly repayment is smaller than a monthly one, but you make 26 a year instead of 12. It also changes the timing of payments, which affects how quickly interest is charged and the total interest paid over the loan.

You can switch between monthly, fortnightly and weekly above to compare. The effect on total interest depends on your loan and how your lender applies payments, so treat any difference as an indication rather than a guaranteed saving.

How to use this mortgage calculator

• • Enter your expected loan amount — not sure yet? Our first home buyer affordability calculator estimates the loan you may need.
• • Enter an interest rate. Use a rate you have been quoted, or a rate typical of current home loans.
• • Choose a loan term, commonly 25 to 30 years.
• • Choose a repayment frequency — monthly, fortnightly or weekly.
• • Change any input to compare scenarios and see how each one affects the repayment, total paid and total interest.

Once a repayment looks manageable, our first home buyer checklist helps you keep track of the other steps in buying.

Important limitations

This calculator provides estimates only. Actual loan repayments can vary depending on the lender, loan structure, fees and charges, interest-rate changes over the life of the loan, and features such as offset accounts, redraw or extra repayments. It assumes the interest rate stays the same for the whole term and includes no fees.

Use it to understand roughly what a loan could cost, not as a loan offer, quote or approval. For exact figures, ask your lender for a loan illustration based on a specific product.