Property Calculators
Three core calculators for Australian property buyers and investors: a mortgage repayment estimator covering principal-and-interest loans across any term and rate, a state-by-state stamp duty calculator using current NSW, VIC, QLD, WA, SA, TAS and ACT bracket schedules, and a borrowing power estimator that applies the APRA 3% serviceability buffer to your declared income and expenses. All inputs run locally in your browser — nothing is sent to a server, and no figures are stored. Results are indicative only and do not account for lender-specific policies, LMI, offset benefits, government concessions, or your individual credit profile. Always confirm numbers with a licensed mortgage broker, financial adviser or conveyancer before committing to a property purchase or loan application.
Key Takeaways
- Every $100,000 borrowed adds roughly $620 a month at 6.29% over 30 years, before LMI on loans above 80% LVR.
- Switching from monthly to fortnightly repayments cuts about two years off a 30-year loan by squeezing in a thirteenth monthly payment each year.
- APRA forces lenders to assess serviceability at your rate plus a 3% buffer, which trims maximum borrowing capacity by around 30% versus the headline rate.
- First home buyer stamp duty thresholds vary sharply by state — NSW exempts under $800,000, VIC under $600,000, QLD under $700,000, ACT abolished it under income tests.
- All calculations run locally in your browser; no inputs are sent to a server, but figures are indicative only and exclude lender-specific policies, LMI, offset benefits and government concessions.
Mortgage Repayment
How this calculator works
Uses the standard amortising loan formula to calculate fixed monthly principal-and-interest repayments. Total interest is the sum of repayments minus the original loan amount.
What affects your repayments
- Loan amount — every $100k borrowed adds roughly $620/month at 6.29% over 30 years. Borrowing more than 80% of the property value also triggers Lenders Mortgage Insurance, which can add tens of thousands to the loan. A larger deposit reduces both the monthly repayment and the total interest paid over the life of the loan.
- Interest rate type — variable moves with the RBA cash rate, so repayments can rise or fall every month. Fixed locks repayments for a set term (typically 1–5 years), giving certainty but with break costs if you refinance early. Split loans let you hedge by fixing part of the balance and leaving the rest variable to keep offset and redraw flexibility.
- Loan term — extending from 25 to 30 years lowers the monthly repayment but adds roughly 8% to total interest paid. Shorter terms build equity faster and reduce lifetime interest, but require higher monthly cashflow. Most lenders cap owner-occupier terms at 30 years and investor terms at 30 years interest-only periods of up to 5 years.
- Repayment frequency — switching from monthly to fortnightly repayments saves roughly 2 years off a 30-year loan. This works because you make 26 fortnightly payments a year (equivalent to 13 monthly payments instead of 12). Weekly repayments shave off slightly more again, and combining this with an offset account can compound the savings significantly.
Stamp Duty Calculator
First Home Buyer: Full exemption for properties up to $800,000
First Home Buyer exemptions by state
- NSW — First home buyers pay no stamp duty on properties under $800,000 and receive a tapered concession up to $1 million. The exemption applies to both new and established homes, with no income test. You must move in within 12 months and live in the property for at least 12 continuous months.
- VIC — Full stamp duty exemption applies for first home buyers purchasing under $600,000, with a sliding concession up to $750,000. The property must be your principal place of residence for at least 12 months, commencing within 12 months of settlement. Off-the-plan concessions can further reduce duty for new builds.
- QLD — First home buyers pay no transfer duty on homes under $700,000 and receive a partial concession up to $800,000. Vacant land concessions apply up to $350,000. You must move in within one year and live there for a continuous 12-month period to retain the concession.
- SA — South Australia does not offer a stamp duty exemption for established home purchases by first home buyers. However, full duty relief is available on new builds and vacant land used to construct a new home, with no price cap announced in the most recent state budget. The $15,000 First Home Owner Grant remains available for new builds.
- WA — First home buyers pay no transfer duty on established homes under $430,000 and vacant land under $300,000, with concessions tapering off at $530,000 and $400,000 respectively. The property must be occupied as the principal place of residence within 12 months. WA also offers the $10,000 First Home Owner Grant for new builds.
- ACT — The ACT abolished stamp duty for eligible first home buyers across all property types and price points under the Home Buyer Concession Scheme, subject to household income limits (currently around $250,000 for one or two dependants). Both new and established properties qualify. You must live in the home for at least one continuous year, starting within 12 months of settlement.
Borrowing Power
Estimate based on 80% of surplus income with APRA's 3% serviceability buffer
Estimated Borrowing Power
$678,315
Based on assessment rate of 9.29% (rate + 3% buffer)
How borrowing power is calculated
Australian lenders apply APRA's serviceability buffer — they must assess your ability to repay at your actual rate plus an additional 3% (currently 9.29% on a 6.29% loan). This protects against future rate rises but cuts maximum borrowing capacity by roughly 30% compared with the headline rate.
Lenders count expenses using the higher of your declared living costs or the Household Expenditure Measure (HEM) benchmark — a statistical estimate based on income, postcode and household composition. Existing debts (credit cards, BNPL, car loans, HECS) all reduce capacity, with credit card limits assessed at 3% of the limit per month even if you owe nothing.
Four ways to lift borrowing power:
- Pay down or close credit cards and BNPL accounts.
- Reduce credit card limits (not just balances).
- Document additional income — bonuses, overtime, rental, side income.
- Extend the loan term from 25 to 30 years.
Understanding Loan-to-Value Ratio (LVR)
LVR is your loan amount divided by the property value, expressed as a percentage. A $560,000 loan against a $700,000 property is an 80% LVR. Lenders use LVR to price risk: the higher the LVR, the higher the interest rate and the more conditions attach to the loan.
Three thresholds matter in Australia. Above 80% LVR, you trigger Lenders Mortgage Insurance (LMI) — a one-off premium protecting the bank, not you, that can cost $15,000–$30,000 on a typical purchase. Above 90% LVR, LMI becomes very expensive (often $25,000–$45,000) and lender appetite narrows. Above 95% LVR very few lenders will lend at all, and the few that do require strong serviceability and a clean credit file.
On a $700,000 property, going from a 10% to a 20% deposit saves approximately $25,000–$35,000 in LMI alone, before counting the lower interest rate that typically applies below 80% LVR. Refinancing also resets your LVR — if your property has grown in value, your loan-to-value ratio may have dropped below 80% even if you have not paid down the principal, unlocking a refinance to a sharper rate. Always order a current valuation before refinancing.
Interest-Only vs Principal and Interest
With interest-only (IO), you pay only the interest charge each month — the principal balance does not move. With principal and interest (P&I), each repayment chips away at both interest and the loan balance, building equity over time. P&I is the standard structure for owner-occupier loans; IO is most common for investment loans.
Investors have historically used IO loans to maximise tax-deductible interest during the IO period and preserve cashflow for further property purchases. The trade-off is that no equity is built through repayments — capital growth is the only path to wealth creation, and if growth disappoints, you finish the IO term with the same debt you started.
The IO term is capped at five years for most lenders, after which the loan reverts to P&I over the remaining term — meaning a 30-year loan with five years IO becomes a 25-year P&I loan, and repayments can jump 30–50%. APRA's 2017 restrictions limited new IO lending to 30% of bank flows, narrowing investor access. Most owner-occupiers should avoid IO entirely — without the tax shelter that justifies it for investors, you are paying interest on a loan that is not getting any smaller.
| Feature | Interest-Only | Principal & Interest |
|---|---|---|
| Monthly repayment | Lower (interest only) | Higher (interest + principal) |
| Loan balance over time | Stays the same | Reduces each repayment |
| Equity build | Only via capital growth | Repayments + growth |
| Tax deductibility (investors) | Maximised | Reduces over time |
| Term limit | Typically 5 years max | Full loan term |
| Best suited to | Investors with growth strategy | Owner-occupiers, conservative investors |