Australia Mortgage Repayment Calculator (with Offset)
Find your home loan repayment and see how extra repayments and an offset account save interest.
How to use this home loan calculator
Enter the amount you want to borrow, the interest rate and the loan term, and choose whether you repay monthly, fortnightly or weekly. The calculator shows your repayment for each period, the total interest over the life of the loan, and the effect of two things many Australian borrowers use to pay less interest: extra repayments and an offset account.
How the repayment is worked out
Repayment = loan × r ÷ (1 − (1 + r)^−n), where r is the interest rate for one repayment period (the yearly rate ÷ the number of repayments a year) and n is the total number of repayments. For a $600,000 loan at 6.0% over 30 years, the monthly repayment is $3,597.30, and the total interest is about $695,029, more than the amount borrowed.
| Option | Time to pay off | Total interest | Interest saved |
|---|---|---|---|
| Repayments only (no extras) | 30 years 0 months | $695,029 | $0 |
| Extra $200 a month | 26 years 1 months | $588,336 | $106,693 |
| $50,000 in an offset account | 25 years 3 months | $491,313 | $203,716 |
Monthly, fortnightly or weekly?
Paying more often lowers your interest slightly because the balance falls sooner. A true fortnightly repayment on the loan above is about $1,659.50. Some lenders offer “accelerated” repayments, such as half the monthly amount every fortnight, which adds up to one extra monthly payment a year (26 half-payments equal 13 months) and shortens the loan a lot. To model that, add the difference as an extra repayment.
What it does not include
- Stamp duty, lenders mortgage insurance, application and ongoing fees.
- Rate changes. With a variable rate, your repayment will change when the rate does, so try a few rates.
- Daily interest calculation. Lenders work out interest daily and charge it monthly, so real figures differ slightly.
This is an estimate for planning, not financial advice. For a loan decision, check the figures with your lender or a mortgage broker. If you also want to see your pay after tax, use the Australia take-home pay calculator.
Frequently asked questions
How do I calculate my mortgage repayment in Australia?
Use repayment = loan × r ÷ (1 − (1 + r)^−n), where r is the rate per period and n is the number of repayments. The calculator does this for monthly, fortnightly or weekly repayments.
How much interest does an offset account save?
An offset account balance reduces the amount your interest is charged on. For example, $50,000 in offset on a $600,000 loan at 6% over 30 years saves tens of thousands of dollars and shortens the loan by several years.
Is it better to pay fortnightly or monthly?
Paying more often saves a little interest. Paying half the monthly amount every fortnight saves much more, because it adds one extra monthly payment a year.
What do extra repayments do?
Every extra dollar goes straight to the principal, so you pay interest on less for the rest of the loan and finish earlier.
Does this include stamp duty or fees?
No. It covers principal and interest only. Add stamp duty, insurance and fees separately.
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