Start with the cash you actually commit
A $600,000 property funded by a $480,000 loan needs a $120,000 deposit, plus purchase costs and any cash held in offset. Comparing it with a $600,000 share portfolio would give the share option a much larger starting budget.
Illustration with no offset balance. Use your actual buying costs and borrowing amount.
Match the money added along the way
If a property needs another $12,000 each year to cover its bills, you could also invest that money in the alternative. BrickOutlook gives each option the same yearly contribution. Positive property cash flow is retained and earns the entered savings rate.
At the end, the property outcome includes sale proceeds after selling costs and the remaining loan, plus offset cash and retained cash surpluses. That gives a comparable cash-based endpoint.
Use historical returns as a reference
The ten years to 31 December 2025 produced annualised total returns of 9.31% for the S&P/ASX 200 in Australian dollars and 14.82% for the S&P 500 in US dollars. These figures include reinvested dividends. They exclude your fund fees and personal tax.
Those were the returns for that particular decade. Try lower assumptions as well. A smooth calculator line hides the price falls, recoveries and timing that investors actually experience.
Multiply by 100 for a percentage. Doubling over 10 years is about 7.18% a year, not 10%.
US returns need a currency assumption
An Australian investor’s unhedged S&P 500 result also depends on the Australian dollar. A stronger US dollar adds to the AUD return; a stronger Australian dollar reduces it. The calculator keeps the US market return and the annual currency effect separate. Leave the currency effect at 0% to model an unchanged exchange rate.
Compare the commitment as well as the return
| Option | What to consider |
|---|---|
| Property | Borrowing, concentrated exposure, repairs, purchase and sale costs, and time to sell. |
| Share portfolio | Market falls, fund fees, diversification and currency exposure. You can usually sell a portion. |
| Bank savings | Interest-rate changes, account conditions and inflation. Eligible deposits may be protected under the Financial Claims Scheme. |
All comparisons here are before personal tax and capital gains tax. The “today’s dollars” option shows how inflation reduces future purchasing power.
Sources: S&P Australia, S&P US, APRA deposit protection.