Australian mortgage planning

Mortgage Scenario Calculator

Compare repayments, rate changes, offset balances, and extra payments before they affect your budget.

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Calculations run in your browser. NorthVault does not collect or store the values you enter here.

Model the next version of your loan.

Use this to pressure-test your mortgage before rate changes affect your budget.

Loan balance

Offset balance

Loan start date

Current interest rate

Scenario interest rate

Remaining loan term in years

Repayment frequency

Property / asset value

Annual asset growth

Extra repayment per selected frequency

Apply extra repayments to

Base results are calculated without an offset. Offset savings estimate interest charged after the offset balance reduces the interest-bearing balance. Extra repayments can be modelled as either direct loan repayments or deposits into the offset account.

Scenario summary

Results update as you change the inputs.

Base repayment $0.00 per month

Scenario repayment $0.00 per month

Change per payment $0.00 Scenario minus current

Annual cash-flow impact $0.00 Annualised difference

Base interest, no offset $0 Current rate, full balance

Scenario interest with offset $0 Uses selected offset balance

Savings with offset $0 Versus same rate without offset

Time saved No extra repayment Offset and extra repayment impact.

Comparison table

A lightweight view of repayments, estimated interest, total paid, loan balance, and estimated asset growth under each scenario.

Balance and asset value over time

Lines are sampled yearly from the simplified repayment model. Asset value uses the growth assumption above.

Scenario	Interest rate	Repayment	Total interest	Total paid

Scenario schedules

Yearly schedule rows show repayments, extra contributions, interest, principal reduction, offset balance, and remaining balance. Export the active tab as a CSV.

Year	Period	Opening balance	Repayments	Extra / offset deposits	Interest	Principal paid	Offset balance	Closing balance	Asset value

Pressure-test the moving parts.

Change the rate, frequency, offset balance, and extra repayment amount to see how each assumption flows through to repayments and estimated interest. The model is intentionally simple, transparent, and local to your browser.

General information only.

This calculator provides general information only and does not consider your personal objectives, financial situation, or needs. It is not financial advice. Real lender repayments can differ because of fees, redraw behaviour, rate changes, package discounts, and lender-specific repayment rules.