Australia Mortgage Repayment Calculator
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Calculate your Australian home loan repayment, weekly, fortnightly or monthly, with the full amortisation formula shown.
Quick answer: Monthly repayment = P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1], where P is the loan amount, r is the monthly interest rate, and n is total monthly payments. A $520,000 loan at 6.2% over 30 years costs about $3,185/month, or roughly $735/week, before any offset account savings.
How to Use the Australia Mortgage Repayment Calculator
Enter the loan amount
Input the amount you need to borrow: the purchase price minus your deposit. Most Australian lenders prefer a 20% deposit to avoid Lenders Mortgage Insurance. If relevant, add any annual body corporate fees or council rates too, so the total shown reflects your real periodic cost.
Set the interest rate and term
Use the actual rate from your lender's quote or pre-approval, not an estimate. Australian home loans commonly run 25 or 30 years.
Choose your repayment frequency
Weekly, fortnightly and monthly all cover the same annual amount; pick whichever matches how your lender structures your repayment schedule.
Check total interest over the loan term
The total interest figure shows the real cost of borrowing across the full term, useful for comparing loan terms or deciding whether extra repayments are worth prioritising.
How Australian Home Loan Repayments Are Calculated
A home loan repayment consists of principal (repaying the amount borrowed) and interest (the cost of borrowing), calculated using the standard loan amortisation formula used by every Australian lender.
📐 Repayment Formula
r = 6.2% / 12 = 0.005167; n = 360
M = $520,000 × [0.005167 × (1.005167)³⁶⁰] ÷ [(1.005167)³⁶⁰ − 1]
M ≈ $3,185/month
Weekly and Fortnightly Repayments Explained
Australian lenders quote and accept repayments weekly, fortnightly or monthly, a genuine structural difference from the US, where monthly is the near-universal default. Splitting the same annual repayment into 52 weekly or 26 fortnightly instalments doesn't by itself change the total interest paid; it's arithmetically the same annual amount in smaller pieces. On the $520,000 example above, that's roughly $735/week or $1,470/fortnight. Real savings come from a genuinely accelerated schedule: 26 fortnightly payments of the same amount as half a monthly payment add up to one extra monthly repayment a year, which does reduce total interest and shorten the loan term.
What Deposit Do You Need in Australia?
Most Australian lenders prefer a 20% deposit to avoid Lenders Mortgage Insurance (LMI), a one-off premium protecting the lender, not the borrower. Under the First Home Guarantee, eligible first home buyers can borrow with just 5% deposit and no LMI. The scheme dropped its place and income caps on 1 October 2025; a property price cap by location still applies.
25-Year vs 30-Year Loan Term: Which Saves More?
| Feature | 25-Year Loan | 30-Year Loan |
|---|---|---|
| Repayment amount | Higher | Lower |
| Total interest paid | Less | More |
| Best for | Borrowers who can service a higher repayment | Maximising borrowing capacity or cash flow flexibility |
What Is an Offset Account?
An offset account is a savings account linked to the home loan; its balance is subtracted from the loan balance before interest is calculated, without changing the required repayment. Because the repayment doesn't shrink, more of each payment goes towards the loan, reducing total interest and shortening the loan term. This calculator shows the standard repayment without an offset.
How Extra Repayments Change an Australian Home Loan
Beyond the standard $520,000-at-6.2%-for-30-years example above, consider adding an extra $100 a week to the repayment. The unmodified weekly repayment is roughly $735, with total interest of approximately $624,000 over the full 30-year term. Applying the extra $100 weekly consistently from the start of the loan pays it off in roughly 22 years instead of 30, nearly 8 years early, cutting total interest by close to $193,000. Most Australian variable-rate home loans allow unlimited extra repayments without a penalty; many fixed-rate loans instead cap penalty-free extra repayments, with the exact cap set by the individual lender's loan contract, so check your own loan documents rather than assuming a figure. Enter your own extra amount in the calculator's Extra Repayment field above to see the exact new payoff time and interest saved for your loan, rather than relying on this fixed example.
Why does an extra repayment made early in the loan save more than the same amount paid later?
Every dollar applied to principal today stops accruing interest for every remaining week of the loan: an extra $100 paid in week 1 saves interest across all remaining weeks of the term, while the identical $100 paid a decade later only saves interest for the weeks left after that point. This is the same reason genuinely accelerated fortnightly repayments (26 fortnightly payments, not simply "half the monthly amount twice a month") outperform standard monthly repayments over the life of the loan.
Frequently Asked Questions
Sources & Methodology
Calculations use the standard loan amortisation formula. Deposit, LMI and First Home Guarantee figures reference publicly available Australian government and industry sources: