Cap Rate vs Cash-on-Cash Return: A Worked Example for Australian Property Investors
September 15, 2026
If you've spent any time researching property investment, you've hit both terms — cap rate and cash-on-cash return — often used almost interchangeably. They're not the same measurement, and mixing them up leads to comparing two properties on different scales without realizing it.
Cap rate ignores how you paid for the property
Capitalization rate is Net Operating Income divided by the property's value or purchase price:
Cap Rate = NOI ÷ Purchase Price
NOI is rental income minus operating expenses — but not minus mortgage payments. That's deliberate. Cap rate is designed to answer one specific question: how does this property's income compare to its price, treating it as a stand-alone asset, regardless of whether you paid cash or financed 90% of it. That's what makes it useful for comparing two different properties to each other — a $2M property financed with a 20% deposit and a $2M property bought outright have the same cap rate if their NOI is the same, even though the actual investor experience is completely different.
Cash-on-cash return measures your actual experience
Cash-on-cash return answers a different question: given how you actually financed this specific deal, what return are you getting on the cash you personally put in?
Cash-on-Cash Return = Annual Pre-Tax Cash Flow ÷ Total Cash Invested
Annual pre-tax cash flow is NOI minus mortgage payments (principal and interest) — the actual cash left in your pocket each year. Total cash invested is your deposit plus closing costs, not the full purchase price.
Worked example
Say you're looking at a property priced at $650,000, with NOI of $32,500 a year.
Cap rate: $32,500 ÷ $650,000 = 5.0%
Now say you put down a 25% deposit ($162,500) plus $15,000 in closing costs and loan fees, so your total cash invested is $177,500. Your mortgage on the remaining $487,500 costs $28,600 a year in principal and interest.
Annual pre-tax cash flow: $32,500 − $28,600 = $3,900
Cash-on-cash return: $3,900 ÷ $177,500 = 2.2%
Same property, same NOI, two genuinely different numbers — and neither one is "wrong." The cap rate (5.0%) tells you how the asset itself performs, useful for comparing it against other properties regardless of financing. The cash-on-cash return (2.2%) tells you what you specifically are earning on the cash you put in, given today's borrowing costs. If you'd put down 40% instead of 25%, your cash-on-cash return would drop even further relative to a smaller deposit scenario at the same interest rate, because you'd have more cash tied up earning the same dollar amount of cash flow — a real trade-off between leverage and return that cap rate alone never shows you.
Why this trips people up in practice
A common mistake is using a strong cap rate as the whole pitch for a deal without checking what it actually returns on the cash going in. In a higher-interest-rate environment, a property with a perfectly respectable 5–6% cap rate can produce a cash-on-cash return close to zero, or negative, once real financing costs are factored in — the mortgage payment can eat nearly all the NOI. That's not a flaw in the property; it's a mismatch between how it was financed and what return that particular deal structure delivers. Run the cap rate to compare properties against each other, and the cash-on-cash return to check whether the specific deal in front of you, financed the way you're actually planning to finance it, clears the bar you need it to clear.
Our Cap Rate Analyzer calculates both live, side by side, along with GRM, expense ratio and DSCR, so you can see how changing the deposit or interest rate shifts the cash-on-cash number without touching the cap rate at all.
This article is general educational information, not investment advice. The worked example uses illustrative figures only — always model your own numbers before making a real decision, and speak to a licensed financial or mortgage adviser about your specific situation.