Mortgage Repayment Calculator

Calculate your mortgage repayments

Are you trying to determine how much your home loan repayments will cost every month, or the total interest you’ll pay over the life of your mortgage? Sounds like you need a mortgage calculator.

Our home loan repayment calculator might be just the thing to help you better manage your mortgage in the years ahead. To use this online mortgage calculator: enter your expected loan amount, interest rate, home loan term, payment frequency, and choose either principal and interest or interest only.

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Please Note: The calculations do not take into account all fees and charges. The results provided by this calculator are an estimate only, and should not be relied on for the purpose of making a decision in relation to a loan. Interest rates and other costs can change over time, affecting the total cost of the loan. Consider whether you need financial advice from a qualified adviser.

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What can you do with a borrowing power calculator? Find out how much you could borrow in a home loan at different interest rates, loan terms, and income levels, with our CANSTAR Borrowing Power Calculator.

The CANSTAR Borrowing Power Calculator calculates a hypothetical maximum loan amount that a borrower could apply for, based on the income and expenses entered into the calculator. This is called your borrowing power.

Financial institutions in Australia are legally required to ensure that you have enough dispensable income available to make certain monthly repayments before they can offer you a home loan.

You can do any number of calculations about your borrowing power for a home loan with the CANSTAR Borrowing Power Calculator. Read on to find out how your borrowing power is affected by different levels of expenses and different terms and conditions on a loan.

How we made our mortgage calculations

The calculations we’ve made are based on inputting the following data into our calculator, except where we have specified otherwise:

  • Your Income: $1,100/week in a single wage household (average working wage according to ABS, 2015: $1,137/week, which equates to $59,124/year)
  • Annual Expenses: $16,500/year (average Australian annual expenses used as default in this calculator)
  • Car Loan Repayment: $0/month
  • Credit Card Repayment: $200/month (average debt $4,300 according to ASIC credit card debt clock at time of writing, means $58/month interest + roughly $100/month repayment if intending to repay debt)
  • Other Expenses: $0/week (assume expenses included above in average Australian annual expenses)
  • Home Loan Interest Rate: 89% (average standard variable interest rate on our database at time of writing)
  • Home Loan Term: 25 years
  • Basic borrowing power based on these figures: $319,000
  • Monthly repayment based on these figures: $1,844/month

The Borrowing Power Calculator includes a calculation to ensure that the borrower’s income could withstand the normal increases in variable interest rates over the life of the loan. Our calculator uses an interest rate buffer of 2.0%.


The values provided can only be taken as an estimate of the amount to be borrowed and does not take into account specific factors used by individual lenders in determining their own criteria.

How much you can borrow is dependent on your personal financial situation, which will differ from the figures we have used in this calculation. You should carefully consider your own income and expenses when using our calculator to find out how much you could borrow.

CANSTAR makes no guarantees that your financial institution of choice will offer you a loan of a particular amount, and you should speak with a financial adviser before making any decisions.

Things to consider when taking out a home loan

How long will your loan term be?

Did you know that if you increase your loan term by just 5 years to a 30-year loan term, you could borrow tens of thousands of dollars more?

For example, by increasing your loan term from 25 years to 30 years, you could borrow $21,000 more and make your monthly repayments $42 cheaper. Of course – this can mean that you end up paying more interest over the life of the loan…

Loan Term You could borrow Monthly repayments
25 years $319,000 $1,844/month
30 years $340,000 $1,802/month

What if you have other loans to repay?

To start with, if you had no other loans or debts to repay apart from your prospective home loan, you might be able to borrow $348,000 on the income and other factors we’ve specified above.

But when you add other loans or debts to the mix, a financial institution offering a home loan will not let you borrow as much on your home loan. Again, this is because they are required to make sure that you do not take on so much debt that you could not afford to repay it.

For example, if you have a car loan with a repayment of $415/month, you may be able to borrow $57,000 less than if you had no debts to repay.

Expenses Cost You could borrow Home loan repayment
No debt $0/month $348,000 $2,012/month
Credit card debt only $200/month $319,000 $1,844/month
Car loan only
($20,000 ataverage rate 8.42%)

rounded to $400/month

$291,000 $1,683/month
Other payments only $1,000/month $205,000 $1,185/month

What will your mortgage interest rates be?

Using our base data input listed above, we can see that changing the interest rate on your loan makes a big difference to how much you can afford to borrow.

If you choose a loan at the minimum variable rate available on our database at the time of writing (for a loan of $350,000), you might be able to borrow $70,000 more than if you choose a loan at the maximum variable rate available.

Interest Rate You could borrow Monthly repayments
3.85%(min variable rate) $352,000 $1,829/month
4.89%(average variable rate) $319,000 $1,844/month
6.31%(max variable rate) $282,000 $1,871/month

Splitting your home loan between variable and fixed interest rates can also make a great difference to how much you can borrow and what you pay in monthly repayments. Try our Home Loan Split Calculator to see how splitting your home loan between variable and fixed interest rates at different amounts can affect your home loan borrowing power.

What if I have a partner? Can we borrow more?

If you have a partner who is also in full-time paid employment at the same average Australian wage, then your borrowing power might more than double.

Of course, with an increased amount borrowed on a home loan comes much larger monthly repayments!

Borrowers should tread very carefully when basing their borrowing power on both partners continuing to earn the same amount. What if the worst should happen and one of you was suddenly unable to work due to being unexpectedly let go, or became seriously sick or injured?

It may be a wise course to base your borrowing power on just one partner’s income, even if it means aiming for a less expensive home in a smaller dwelling or a location further from the city centre. Nobody wants to end up in financial hardship, and a little planning can go a long way towards preventing it.

What if I have kids?

Everyone knows kids make life more expensive, and financial institutions will take this into account when calculating your borrowing power. In our calculator, your annual expenses jump up with your first child, and continue to rise with each additional child.

Having two children could lower your borrowing power by $93,000 if you live in a single wage household.

Number of dependants Annual expenses expected You could borrow
0 $16,500 $319,000
1 $20,400 $273,000
2 $24,300 $226,000

Having said that, at the time of writing, households with a weekly income of $1,022/week ($2,044/fortnight) are eligible for a part-payment of the government Parenting Payment from Centrelink. This additional income may increase your borrowing power slightly.

More home loan calculators to help you work out your financial position

Use CANSTAR’s home loan calculators when you’re doing your sums about how much you can afford to borrow in a home loan:

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