Home Loan Calculator
Work out a rough monthly repayment before you talk to anyone. Enter the loan amount, an indicative interest rate, and the term, and the calculator below returns an estimated repayment and the total interest you would pay over the life of the loan. It takes about thirty seconds. The number it gives you is a starting point, not an approval, and it costs you nothing to run as many scenarios as you like.
A word on what we do. Windsor Finance is a finance broker, not a lender. We arrange property finance through a panel of Australian bank and non-bank lenders, and our focus is investment, development, commercial, and SMSF property lending rather than standard owner-occupier home loans. Use this tool to size up any property loan. When the deal is investment or business-purpose, that is exactly the kind of finance we place.
What this calculator estimates
The calculator runs the standard amortising loan formula that every lender uses. You give it three inputs and it returns three outputs.
Inputs:
- Loan amount: the figure you intend to borrow, after your deposit or equity.
- Interest rate: an indicative annual rate. Rates move daily and vary by lender, loan type, and your circumstances.
- Loan term: the repayment period in years, commonly 25 or 30 for residential, shorter for commercial and bridging.
Outputs:
- Estimated repayment per month (or per fortnight, if you switch the frequency).
- Total interest paid across the full term.
- Total cost of the loan, being principal plus interest.
The result assumes a principal-and-interest repayment at a fixed rate held for the whole term. Real loans rarely behave that cleanly. Rates change, you may pay interest-only for a period, and fees sit outside the repayment figure. Treat the output as a guide to the order of magnitude, not a quote.
How to use it
Start with the property price and subtract your deposit or available equity to get the loan amount. For an investment purchase, most lenders want genuine equity of 20% to 35% depending on the security and the structure, so the loan amount is usually 65% to 80% of the price.
Pick an interest rate that matches the loan type. Prime investment lending sits around 6% to 8% per annum on an indicative basis. SMSF loans price higher, roughly 6.5% to 9%, reflecting the limited-recourse structure. Bridging and private finance are short-term money and run higher again. The product pages linked below carry the indicative ranges for each type.
Set the term, then read the repayment. Now change one input and watch the number move. A half-percent rate rise on a $700,000 loan over 30 years adds real money to the monthly figure. Seeing that swing is the point of the exercise. It tells you how much headroom your budget needs before rates do anything you cannot control.
What actually affects the result
Three things drive the repayment, and one of them you can influence more than you think.
The interest rate matters most over a long term, because interest compounds across hundreds of payments. The loan amount is the obvious lever. The term is the quiet one. Stretching a loan from 25 to 30 years lowers the monthly repayment but raises the total interest, sometimes by tens of thousands of dollars. A shorter term costs more each month and far less overall.
What the calculator does not show is just as important. It excludes the establishment or application fee, the valuation fee, the lender’s legal costs, the line fee on construction and development facilities, and Lenders Mortgage Insurance, which can apply on standard investment lending above 80% LVR. It also assumes one rate for the whole term. If you fix for two years and revert to a variable rate, the real repayment changes when the fixed period ends. Every one of these costs is disclosed in writing, up front, before you commit.
The Australian context
A few terms matter here. Lenders assess your borrowing against an LVR, the Loan-to-Value Ratio, which is the loan as a percentage of the property’s value. They also apply a serviceability buffer, testing whether you could still meet repayments at a rate two to three percent above the actual rate. Investor lending attracts a tighter buffer than owner-occupier lending, so the amount a calculator says you can repay and the amount a lender will advance are often different numbers.
Settlement is the AU term for completion, the day funds change hands. For an SMSF purchase under a Limited Recourse Borrowing Arrangement, the fund acquires a single property held in a separate bare trust, and the LVR caps sit lower, around 70% for residential and 65% for commercial SMSF security. The repayment maths is the same. The structure and the lending rules are not. SMSF borrowing needs independent financial and tax advice before you proceed, and Windsor does not give that advice.
This is also where a calculator stops being useful. It cannot read your security, your income evidence, or your exit. A broker can.
Why a calculator is only step one
The number on the screen is generic. It does not know that your income is self-employed and lumpy, that the property is a regional or non-standard security, or that you need to settle in three weeks. It cannot tell you which lender on a panel will say yes to your structure, or at what rate. Going direct to one bank gets you that bank’s single answer. A broker takes one enquiry to banks, non-bank lenders, and private credit funds at once, then packages the file so the right lender sees a clean case first time.
That is the difference between an estimate and a real assessment. The calculator gives you the shape of the deal. We give you the lender who will fund it.
Frequently asked questions
Is this a home loan approval? +
Why does the calculator amount differ from what a lender will lend me? +
Does the repayment include fees? +
Can I use this for an SMSF or investment loan? +
Is Windsor Finance a lender? +
Get a real assessment, not just an estimate
Run the numbers above, then let a broker pressure-test them against the live market. In a 15-minute call we will look at your deal, talk through the likely lenders, and come back with indicative structures inside 24 to 48 hours. No cost, no obligation.