Flip ROI calculator

What is flip ROI?

Flip ROI is the return on investment you earn from a property renovation, expressed as a percentage. The formula itself is simple: (sale price − total costs) ÷ total costs × 100. If a deal costs you $760,000 all in and sells for $840,000, your $80,000 profit is a little over 10% return on the money you put in. The number only means something, though, if the total costs half of the equation is honest — and that's exactly the half flippers routinely under-count. Stamp duty, holding costs, selling costs and tax quietly eat the headline gain, and leaving any of them out doesn't make the deal better. It just makes your ROI a fiction.

What counts as a total cost?

Every dollar that leaves your pocket between offer and settlement of the resale belongs in total costs. The calculator above breaks them into the buckets that matter:

• Purchase price — the biggest lever in the whole deal. You make your money when you buy, not when you sell.
• Stamp duty — often tens of thousands, and it varies by state and price bracket. If you're not sure of yours, run it through the stamp duty calculator first.
• Acquisition costs — conveyancing, legals, building and pest inspections, and any lender or valuation fees.
• Renovation cost — the works budget, ideally with a contingency baked in for the surprises behind the walls.
• Holding costs — interest, council rates, insurance and utilities for the entire hold, from settlement to sale. The longer the project runs, the more this quietly grows; the holding cost calculator breaks it down month by month.
• Selling costs — agent commission, marketing and conveyancing on the way out.
• Tax — the one most people forget to model until it's too late (more on that below).

Skip any one of these and your ROI inflates. The discipline of a good feasibility isn't optimism; it's refusing to let a cost disappear just because it's inconvenient.

ROI on total cost vs cash-on-cash return

This calculator gives you return on total cost — profit divided by every dollar the project consumes. That's the cleanest way to compare one deal against another because it ignores how the deal is funded. But it isn't the same as your cash-on-cash return, which measures profit against the actual cash you tipped in: your deposit, the costs the loan didn't cover, and the reno spend you funded yourself. Because most flips are leveraged, cash-on-cash is usually the higher, more flattering number. Neither is wrong — they answer different questions. Use return-on-cost to rank deals on their merits, and cash-on-cash to understand what the deal does for your own bank balance.

What's a "good" flip ROI in Australia?

There's no official benchmark, and anyone quoting you a single magic percentage is guessing. What matters is whether the margin is thick enough to survive the things that go wrong — because on a flip, something usually does. A return that looks healthy on paper can evaporate if the reno runs 20% over, the market softens while you're holding, or the sale takes two months longer than planned. That's why experienced flippers build in a buffer rather than chasing the thinnest deal that still technically pencils. A useful habit: after you've got your ROI, stress-test it. Knock 5% off the sale price, add 15% to the reno, and stretch the timeline by a few months. If the deal still makes money under that pressure, it's a real margin. If it only works when everything goes perfectly, it doesn't.

Don't forget the tax line

The tax field trips up more first-time flippers than any other. Many assume they'll pay capital gains tax and claim the 50% discount — but for most genuine flips, the ATO treats the profit as ordinary income, taxed at your full marginal rate, with no CGT discount at all. Get that wrong and your after-tax ROI can be far lower than the gross number suggests. It's worth reading how the ATO treats flipping profit and, if a substantial renovation is involved, whether GST applies to your sale, before you settle on a tax figure. For a directional CGT estimate, the CGT calculator gives you a starting point.

The mistakes that inflate flip ROI

The recurring errors are predictable. Using an optimistic sale price instead of a defensible one — feed this calculator your after-repair value from real comparable sales, not the number you're hoping for. Under-budgeting the reno because you've never run one at that scope. Forgetting that holding costs keep accruing every week the project slips. And leaving tax out entirely. Each of these makes the ROI look better and the deal look safer than it is, which is exactly backwards.

How FlipPro does this for you

The FlipPro app pulls comparable sales to estimate your sale price, runs stamp duty against the right state bracket, calculates holding cost from your loan and timeline, and models the tax position — so you get the same answer in under a minute, on a real listing, instead of typing a dozen numbers into a spreadsheet. To see the full workup on an actual deal, walk through the sample analysis, or let FlipPro's full analysis build the whole feasibility for you. New to flipping? Our complete guide to flipping a house in Australia walks through every cost in this calculator, step by step, and the 70% rule calculator sets your walk-away buy price before you ever run the return.

This is general information, not financial, tax or investment advice. Flip ROI is an estimate — verify your own costs and get professional advice before you commit to a purchase.