Work out your weekly, fortnightly or monthly home loan repayments. See exactly how much interest you'll pay over the life of the loan — and how much you save by adding even small extra repayments. Pure JS, no signup, results update as you type.
Uses the standard Australian P&I formula M = P·r(1+r)^n / ((1+r)^n − 1). Fortnightly is calculated as half the monthly repayment paid 26 times a year — the way major Australian lenders structure it, which is why it pays down faster than 12 monthly payments. Extra repayments are simulated period-by-period against the actual amortisation schedule. Results are indicative — confirm the exact figure with your lender.
Enter your loan details to see repayments, total interest, and savings
Mortgage is only half the picture. See stamp duty, LTO fees, conveyancer, inspections, LMI and every other dollar you need at settlement.
Open the tool →Before you set the loan amount, check the agent's price guide against the real suburb median. Don't borrow more than the place is worth.
Open the tool →FHOG, stamp duty concessions, the LMI waiver. Every concession stacked, with worked examples for under and over $650k.
Read the guide →Complete SA stamp duty brackets, LTO fees, conveyancer ranges — with worked examples for every price band.
Read the guide →The standard formula is M = P × r(1+r)n / ((1+r)n − 1), where M is the monthly repayment, P is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the total number of months (term in years × 12). This calculator uses the same formula and adapts it for fortnightly and weekly frequencies the way major Australian lenders do.
Most Australian lenders set fortnightly repayments at half the monthly amount. Since there are 26 fortnights but only 24 half-months in a year, you effectively pay an extra month's worth of principal each year — knocking years off the loan term and saving thousands in interest. The savings are automatic; you just choose fortnightly when you set up the loan.
Even small extras compound dramatically. On a $600,000 loan at 6.5% over 30 years, adding $200 per month to the standard repayment cuts the term by about 6 years and saves around $185,000 in interest. Use the extra-repayment input above to model your exact scenario — the results table updates as you type.
Principal & Interest (P&I) repayments pay down both the loan balance and the interest each period — at the end of the term, the loan is fully repaid. Interest Only (IO) repayments cover only the interest; the principal stays the same and the loan must be repaid (or refinanced to P&I) at the end of the IO period (usually 1–5 years). P&I is the default for owner-occupiers. IO is more common for investment loans where the borrower wants lower repayments and is relying on capital growth.
No — this calculator focuses on the repayment maths only. For the full purchase cost (stamp duty, LTO fees, conveyancer, building inspection, Lenders Mortgage Insurance, moving costs and more) open the All-In SA Cost Calculator.
No. SA Property Central is not a lender, broker, or credit provider. This calculator is an information tool only. Actual rates, fees, and approval depend on your lender's assessment. Always confirm figures with your bank or broker before committing.
Yes for the maths — it's a standard amortisation schedule (P&I or interest-only). What's NOT modelled is offset accounts, redraw, fee changes, or variable rates moving differently from the base rate.
Use the rate you've been quoted by your lender. If you haven't shopped yet, the major SA lenders publish their owner-occupier P&I rates publicly; the RBA cash rate target is a useful baseline.
Yes. APRA requires lenders to assess borrowers at the contract rate plus a 3% buffer, so seeing what a 3-point rise does to your repayment is a sensible check before signing.
No — this tool models the loan repayment only. For the all-in cost of buying including stamp duty, use the True Cost Calculator.