Home loan repayment calculator
Estimate your monthly home loan repayment, and see how much of it is interest, from the loan amount, interest rate and term.
Total repaid: $0
Estimate only, for general information and not personal financial advice. It assumes a constant interest rate and principal-and-interest repayments, and excludes fees, offset, redraw and future rate changes. Last checked June 2026.
How the calculator works
The calculator uses the standard amortisation formula that banks use to work out a principal-and-interest repayment. It takes the loan amount, divides the annual interest rate into a monthly rate, and spreads the loan evenly across the number of months in the term so the balance reaches zero at the end. Most of your early repayments go to interest, and the share going to principal grows over time.
What it does not include
Treat the result as a guide, not a quote. It does not include application or ongoing fees, Lenders Mortgage Insurance if your deposit is under 20 per cent, the effect of an offset account, or any change in your rate over a 25 or 30 year loan. Lenders also assess you on a higher rate than the one you pay, the serviceability buffer, which is why your approved amount can be lower than these numbers suggest.
How to lower your repayments
The biggest lever is the rate. If your current rate is higher than what new customers are offered, you are paying the loyalty tax, and refinancing or negotiating can save more than years of small extra payments. After that, extra repayments and an offset account do the heavy lifting. The full playbook is in how to pay off your mortgage faster, and the wider picture is in our complete home loans guide.
The bottom line
Use the calculator to compare scenarios, a lower rate, a shorter term, a bigger deposit, and see what each does to the repayment and the total interest. When you are ready for real numbers, compare lenders with a tool like Your Finance Guide before you commit.