Mortgage Calculators
Crunch the numbers before you commit. Repayments, borrowing power, stamp duty, and LVR, all free, all updated for 2025 rates.
Mortgage Repayment Calculator
See your weekly, fortnightly, and monthly repayments instantly. Adjust the loan amount, interest rate, and term to explore different scenarios. Paying fortnightly instead of monthly can save years off your loan.
- Weekly, fortnightly & monthly breakdowns
- Total interest paid over the loan term
- Covers loans from $50k to $2M
- Useful for refinance comparisons too
Repayment Calculator
Estimates only. Rates and repayments may vary. Seek professional advice.
Borrowing Power Calculator
Get a rough estimate of how much you could borrow. Results are indicative only. Book a call for an accurate assessment.
Uses a 9% assessment rate (actual + 3% buffer). Indicative only. Not financial advice.
Borrowing Power Calculator
Find out how much a lender might offer you based on your income, expenses, and existing debts. The result is an estimate. A broker pre-approval will give you the lender's actual figure.
- Accounts for dependants and living costs
- Factors in existing debts and credit cards
- Single and dual-income households
- Based on current lender assessment rates
QLD Stamp Duty Calculator
Queensland transfer duty (stamp duty) is one of the biggest upfront costs in buying a home. First home buyers may pay nothing, but the threshold is specific. Get your exact figure here.
- First home buyer concession applied automatically
- Owner-occupier and investor rates
- Updated for 2025 QLD thresholds
- Shows full upfront cost breakdown
Stamp Duty Calculator (QLD)
Calculate Queensland transfer duty and first home buyer concessions. Note: Rates may change: verify with QLD Revenue Office before relying on these figures.
Indicative only. Based on QLD 2024–25 rates. Verify with the QLD Office of State Revenue before relying on these figures.
LVR Calculator
Calculate your Loan-to-Value Ratio and see if you'll need Lenders Mortgage Insurance.
LMI likely required
With LVR above 80%, most lenders require Lenders Mortgage Insurance. Estimated LMI: $7,020 (can usually be added to the loan). Alternatively, the First Home Guarantee allows 5% deposit without LMI for eligible first home buyers.
LMI estimate is indicative only. Actual LMI is determined by the lender's insurer.
LVR & LMI Calculator
Your Loan to Value Ratio (LVR) determines whether you need Lenders Mortgage Insurance. At 80% LVR or below, most lenders waive LMI, saving you thousands. See exactly where you stand.
- Instantly shows your LVR percentage
- Estimates LMI premium if applicable
- Shows whether you hit the 80% threshold
- Helps you plan the right deposit target
Extra Repayments Calculator
Even a small extra payment every month can shave years off your home loan and save tens of thousands in interest. See the exact impact of paying more, and use it to decide whether to contribute more or invest the difference.
- Shows years and months saved on your loan term
- Calculates total interest saved over the life of the loan
- Compares minimum vs boosted monthly repayment
- Works for any loan size from $50k to $2M
Extra Repayments Calculator
See how much time and interest you save by paying extra each month.
Estimates only. Seek professional advice.
Refinance Savings Calculator
See how much you could save by switching lenders
Your results
Ready to refinance?
We compare 60+ lenders to find the sharpest rate for your loan size and situation. Free.
Get a Rate ComparisonRefinance Savings Calculator
Still on the rate you started with? Even a small rate reduction can save you tens of thousands over your remaining loan term. Enter your current loan details and a target rate to see your break-even point and total savings instantly.
- Monthly and annual savings side by side
- Break-even calculation: how many months to recoup costs
- Total interest saved over remaining loan term
- Compares current vs new repayment in one view
Negative Gearing Calculator
Most investment property cost calculators stop at the gross rental shortfall. This one goes further: enter your marginal tax rate to see exactly how much the ATO subsidises your holding costs, and what your real monthly out-of-pocket expense is after the tax rebate.
- Annual rental income vs full deductible costs
- Tax saving at your actual marginal rate (19%–45%)
- Real after-tax monthly shortfall (not the gross number)
- Gross rental yield calculation
- Switches to positive gearing mode when income exceeds costs
Negative Gearing Calculator
19% (under $45k) · 32.5% ($45k–$120k) · 37% ($120k–$180k) · 45% (over $180k)
Annual Cash Flow Breakdown
Out-of-pocket after tax rebate
Interest-only loan assumed. Excludes principal repayments, depreciation claims, and capital gains. Speak with a qualified accountant for personalised tax advice.
More tools from Kookaburra Finance
Everything you need to plan your purchase or refinance.
Calculator FAQs
Common questions about Australian mortgage calculations.
How accurate is the mortgage repayment calculator?
Our repayment calculator uses the standard amortisation formula and gives a precise figure based on the inputs you provide. Real repayments may differ slightly depending on your lender's compounding method (most Australian lenders use monthly or daily), fees, and offset account balances. Use it as a reliable guide, then speak with a broker for lender-specific figures.
What is a good interest rate for a home loan in Australia?
As of 2025, competitive variable home loan rates in Australia typically start from around 5.8–6.3% p.a. for owner-occupiers with a 20%+ deposit. Fixed rates may be higher or lower depending on the term. The best rate depends on your loan size, LVR, employment type, and lender. A mortgage broker can access rates not available to the general public.
How much can I borrow for a home loan?
Borrowing power depends on your gross income, existing debts, living expenses, dependants, and the lender's assessment rate (typically 2–3% above the actual rate). Most lenders will lend you 4–6× your gross household income, but the precise figure varies. Use our borrowing power calculator above for an estimate, then book a call with us for a full lender assessment.
What is LVR and why does 80% matter?
LVR (Loan to Value Ratio) is your loan amount divided by the property's value, expressed as a percentage. At 80% LVR or below, most lenders waive Lenders Mortgage Insurance (LMI), a one-time premium that can add $10,000–$30,000 to your loan. Keeping your LVR at 80% or under is the most common deposit target for home buyers.
Do I pay stamp duty as a first home buyer in Queensland?
Many Queensland first home buyers pay zero stamp duty. The First Home Concession eliminates transfer duty entirely on homes valued under $500,000, with a partial concession up to $550,000. Above that threshold, full transfer duty applies. Use our stamp duty calculator above to see your exact position.
When does refinancing make financial sense?
Refinancing typically makes sense when you can reduce your interest rate by 0.5% or more, and when the total savings over your break-even period outweigh any exit fees and establishment costs. Our refinance calculator above models exactly this: enter your current loan details and a target rate to see your monthly saving, total saving, and break-even point in months.
What is negative gearing and how does the tax saving work?
Negative gearing occurs when the costs of owning an investment property (interest, rates, insurance, management fees) exceed the rental income. The resulting loss is deductible against your other income at your marginal tax rate, which reduces your tax bill. Our negative gearing calculator shows the real after-tax monthly shortfall once that rebate is factored in, giving you a clearer picture of the true ongoing cost.
Numbers look good? Let's make it official.
Book a free 15-minute call with Tom. We'll check your actual borrowing power, compare lenders, and get you a rate the calculator can't show you.