Geoffrey’s Mortgage Calculator

How does this mortgage calculator work?

Enter the property price, your deposit, the interest rate your lender has quoted and the loan term. The calculator works out the loan amount, then shows your estimated repayment weekly, fortnightly or monthly, along with the total interest and total amount repaid over the life of the loan.

Switch between principal & interest and interest only to see the difference. Interest-only repayments are lower each month, but the loan balance doesn’t reduce, so the total interest paid is higher — useful to see side by side before you talk to a broker.

What the calculator doesn’t include

The estimate is based purely on the figures you enter. It does not include:

• Stamp duty (transfer duty), which varies by state and by first-home-buyer concessions
• Lenders Mortgage Insurance (LMI), usually payable on deposits under 20%
• Application, settlement, valuation and ongoing account fees
• Rate changes over the life of the loan — the rate you enter is applied for the full term
• Offset accounts, redraw or extra repayments

Because the interest rate isn’t pre-filled, you’re comparing on the rate you’ve actually been offered, not a headline rate that may not apply to you. For the current cash rate, see the Reserve Bank of Australia.

Who is this mortgage calculator for?

• First-home buyers working out what a deposit and price point mean per fortnight
• Home owners checking whether a refinance offer actually saves money
• Investors comparing interest-only against principal & interest
• Anyone wanting a quick, honest number before speaking to a lender or broker

An estimate, not financial advice. Your borrowing capacity and actual repayments depend on your lender’s assessment, fees and your circumstances. Speak to a licensed lender or mortgage broker before making a decision.

Updates: Calculator reviewed September 2026.

Built by Geoffrey Digital

Want a calculator like this on your own website?

If you’re a mortgage broker, real estate agent, buyer’s agent, builder or financial planner, a calculator gives visitors a reason to stay on your site instead of drifting off to a bank’s. It’s built as a WordPress plugin — no iframes, no third-party branding, no monthly subscription — and styled to match your site.