About the Mortgage Calculator
Estimate what your home loan will cost. Enter the property price, your deposit, the interest rate and the loan term to see the repayment, the total interest over the life of the loan and a year-by-year breakdown of your balance.
Add an extra repayment to see how much interest and time you could save — often tens of thousands of dollars and several years.
How does the Mortgage Calculator work?
The calculator works out the loan amount (price minus deposit) and the fixed repayment that clears it, with interest charged on the outstanding balance, by the end of the term.
Repayments are principal and interest. In the early years most of each repayment is interest; as the balance falls, more of each repayment reduces the loan.
The loan-to-value ratio (LVR) is the loan as a percentage of the property value. Many lenders require mortgage insurance when it’s over 80%.
Mortgage Calculator formula
M = P × r ÷ (1 − (1 + r)^−n)M is the repayment, P the loan amount, r the interest rate per repayment period (annual rate ÷ repayments per year) and n the total number of repayments.
Example
A $600,000 loan at 6.1% over 30 years costs about $3,636 a month, with roughly $709,000 of interest over the life of the loan. An extra $300 a month saves about $151,000 in interest and cuts the loan by about five and a half years.
Tips
- Compare lenders on the interest rate and the fees — a small rate difference adds up over 25–30 years.
- Extra repayments early in the loan save the most interest.
- Remember stamp duty, legal fees and moving costs when working out your deposit.