Property Investment Calculator

Every property investment decision comes down to the same handful of numbers, whether you're weighing up a purchase or reviewing one you already hold: the purchase price, the cash required upfront, your loan and equity position, the rental income, the ongoing costs, the resulting cash flow, the rental yield, and the long-term value and equity the property builds. This calculator walks through exactly those numbers — just in the order that matters for your situation.

Buying costs more than the deposit. On top of your deposit or equity contribution, budget for stamp duty (which varies significantly by state — see our Australian stamp duty guide), conveyancing, building and pest inspections, and loan establishment costs — including Lenders Mortgage Insurance (LMI) if you're borrowing above 80% of the property's value.

A distinction worth understanding early: your deposit is just the equity contribution against the loan. The total cash required to settle is your deposit plus every one of those purchase costs above. Buyers who budget only for the deposit are routinely short by tens of thousands of dollars at settlement.

Purchase costs are one-off. Cash flow is ongoing, and it's the number that determines whether the property is sustainable to hold. On the income side, that's rental income, less an allowance for vacancy. On the cost side, it's loan repayments and interest, property management fees, council and water rates, insurance, strata or body corporate fees (for units), and maintenance.

This is also why a property can have a perfectly respectable rental yield and still be cash-flow negative — yield only measures rent against price. It ignores your loan repayments entirely, which are usually the largest single cost.

The formula itself is simple — it's getting realistic inputs that takes the effort:

Your deposit or equity contribution sets the loan amount, and the loan amount relative to the property's value sets your loan-to-value ratio (LVR) — the single number lenders use most to price risk and decide whether LMI applies. From there, an interest-only period keeps early repayments lower but doesn't reduce the loan balance, while principal-and-interest repayments do both from day one.

As a property grows in value or the loan balance falls, you build usable equity — broadly, the gap between what the property is worth and what you owe, minus a buffer most lenders keep to a target LVR (commonly 80%). That usable equity is what makes refinancing or buying again possible.

A lender's actual decision goes well beyond this maths: it also weighs your income, existing debts, living expenses, the rental income it will count toward serviceability, and its own lending policies. This calculator estimates the equity and repayment mechanics — it does not, and cannot, tell you what a lender would approve.

Gross yield is annual rent divided by property value — a quick, loan-free snapshot of income relative to price. Net yield subtracts ongoing costs (but still ignores the loan) before dividing by price. Cash flowis the only one of the three that includes your actual loan repayments, which is why it's the number that determines what the property costs — or earns — you week to week.

A property can rank well on yield and still be cash-flow negative once real repayments are factored in, or vice versa on an unusually cheap fixed rate. They measure different things and both matter. For a closer look at what counts as a strong number in today's market, see the Rental Yield Calculator.

A single ROI percentage rarely tells the full story on property. A more honest feasibility read weighs the initial capital required, the annual cash flow it produces, its rental yield, an assumed rate of capital growth, how quickly the loan balance falls, the equity that creates over time, and the costs — agent fees, capital gains tax — you'd face on an eventual sale.

No single metric makes a property attractive or unattractive on its own. A low-yield property in a strong growth corridor and a high-yield property with flat growth can both be reasonable investments — they just win on different measures. Run the full picture with the ROI Calculator.

Projecting years ahead means compounding an assumed annual growth rate against today's value to get a future value, then tracking the loan balance down as repayments and any extra payments reduce it. The gap between those two lines — future value minus remaining loan balance — is your projected equity.

The critical word is assumed. Growth rate inputs are a scenario, not a forecast — past growth in a suburb is no guarantee of future growth, and small changes in the assumed rate compound into large differences over 10–20 years. For more control over those assumptions, use the Equity Forecast Calculator.

Used well, this calculator is a fast way to compare scenarios and sanity-check a number.