Property Compass
by Sextant Digital
Property Compass
Mortgage Calculator
Work out your repayments, compare P&I vs interest only, and see how extra payments could get you mortgage-free sooner.
Navigate your next property move
Loan Details
Enter the property and loan details.
Loan amount
$520,000
Pay Off Sooner
See how much time and interest you save by paying extra.
Results
Updates live as you type.
Monthly repayment
$3,202
Annual repayment
$38,421
Total amount repaid
$1,152,623
Total interest paid
$632,623
Years sooner
8.9 yrs
Interest saved
$215,275
Understanding your mortgage
Principal & Interest vs Interest Only
With Principal & Interest, each repayment reduces your loan balance so you build equity over time. Interest Only means your repayments cover only the interest — the loan amount stays the same. IO is popular with investors because repayments are lower and may improve cashflow, but you'll pay more interest overall and won't reduce the underlying debt.
How extra repayments save you thousands
Because mortgage interest is calculated on your outstanding balance, extra repayments directly reduce future interest charges. Even modest additional payments — say $200 a fortnight — can cut years off a 30-year loan and save tens of thousands in interest. The Pay Off Sooner section shows exactly how much you'd save with your own numbers.
After-tax cost for investors
If you're borrowing to invest, the interest on your loan is generally tax-deductible in Australia. This means your real out-of-pocket cost is lower than the headline repayment figure. Toggle to Investment mode and select your marginal tax rate to see your actual after-tax repayment — the amount that truly comes out of your pocket each month. Marginal tax rates here reflect the FY2026-27 ATO brackets, including the rate cut on the $18,201–$45,000 bracket from 16% to 15% effective 1 July 2026.
First home buyer support in 2026
Tick "First home buyer" above to reduce your loan amount by the relevant First Home Owner Grant — a cash payment separate from any stamp duty concession, ranging from $10,000 (NSW, VIC, WA) to $30,000 (QLD) depending on your state, and only available for new builds or vacant land. The ACT doesn't offer a cash grant, but from 1 July 2026 it abolished stamp duty entirely for first home buyers instead.