Mortgage Repayment Calculator Australia 2026: Monthly Payment Guide
Use an Australian mortgage repayment calculator guide for 2026 monthly, fortnightly and weekly repayments, principal-and-interest and interest-only loans.
Mortgage Repayment Calculator Australia 2026
Understanding your mortgage repayment before signing a contract changes what you can confidently offer. A repayment calculator converts the loan amount, interest rate and term into weekly, fortnightly and monthly cash-flow figures.
Principal and Interest vs Interest-Only
The repayment type determines how quickly you build equity and what your minimum payment looks like.
- Principal and interest: each payment reduces the loan balance — you build equity from day one
- Interest-only: payments cover only interest — the balance doesn't reduce during the interest-only term
- Interest-only periods are typically 1–5 years, after which P&I repayments begin on the full remaining balance
Interest-only repayments look lower upfront but result in higher total interest paid and larger P&I repayments when the IO period ends.
Repayment Frequency and Total Interest
Paying fortnightly instead of monthly results in one extra monthly equivalent per year — reducing total interest paid over the life of the loan. On a $500,000 loan at 6% over 30 years, this saves thousands in interest.
| Frequency | Payments/Year | Effect |
|---|---|---|
| Monthly | 12 | Standard |
| Fortnightly | 26 | Equivalent to 13 monthly payments — saves interest |
| Weekly | 52 | Maximum frequency savings |
LMI, Stamp Duty and Upfront Costs
Lenders Mortgage Insurance (LMI) applies when your deposit is below 20% of the purchase price. Stamp duty rates vary by state and property value — and first home buyer concessions may reduce or eliminate it. Both are significant upfront costs to model before budgeting repayments.
Borrowing Capacity Considerations
Banks assess serviceability using a buffer rate — typically the actual rate plus 3% — to stress-test your ability to repay. Your net income after tax, existing debts and living expenses all affect the amount you can borrow.
Use a mortgage calculator alongside a take-home pay calculator to check repayments against your actual net income — not your gross salary.
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