Fix and Flip Calculator

How the fix and flip calculator works

Flipping looks simple from the outside — buy low, renovate, sell high — but the profit hides in a stack of costs that are easy to underestimate. This calculator makes every one of them explicit. It starts from the after-repair value, the price you expect to sell for, then subtracts the four cost groups a flip really carries: the purchase, the rehab, the cost of holding the property month after month, and the cost of transacting on both ends. What survives is your true pre-tax profit.

Two numbers then put that profit in context. ROI measures the profit against everything you sank into the project, and annualized ROI stretches that return to a full-year basis so a quick three-month flip and a slow ten-month one can be compared honestly. If you are weighing whether to flip or hold and rent instead, run the same property through the cap rate and rental property ROI calculators, and use the 70% rule as a fast first screen on the offer price.

The costs flippers underestimate

Most losing flips are not undone by the purchase price or even the rehab — they are undone by holding costs and selling costs, the two that feel invisible until they arrive. Every extra month on the market adds taxes, insurance, utilities and loan interest, so a renovation that runs two months late can quietly erase thousands. Selling costs sting at the finish line: agent commissions and closing fees routinely take 6% to 9% of the sale price straight off the top. Build both in generously from the start, because optimism here is what turns a projected profit into a real loss.

How flippers finance a flip

Most flippers do not pay cash. The usual tool is a short-term hard money loan — asset-based financing priced on the deal rather than your income, typically covering a large share of the purchase and often part of the rehab. It is fast and flexible, but expensive: expect higher interest plus upfront points (a percentage of the loan charged at closing). In this calculator, put the loan interest into the monthly holding cost and the points into buying costs, and the profit and ROI will reflect the real price of leverage. Because a financed deal ties up far less of your own cash, your true return on that cash is usually higher than the project ROI shown here — size it with the hard money loan calculator and the cash-on-cash return calculator.

Reading the return, not just the profit

A big dollar profit is not automatically a good deal. Tying up a large sum for many months to earn a modest percentage can be worse than a smaller flip that turns over quickly, which is exactly why annualized ROI matters. It rewards speed and punishes drift. When you compare deals, look at the profit for whether it clears your minimum, and at the annualized ROI for how hard your money is actually working. And remember the figures here are pre-tax — flips are typically taxed as ordinary income, so your take-home is lower than the headline profit.

Estimate only — not investment or tax advice. Rehab budgets, holding time and sale prices are the biggest risks in a flip; pad your estimates and confirm ARV with local comparables.

How to use it & key terms

Enter the purchase price, rehab budget, holding period and costs, and the sale price and selling percentage, then press Calculate to see the total cost, profit, ROI and annualized ROI.

Building a rehab budget you can trust

Of all the inputs on a flip, the rehab budget is the one people most often get wrong — and because profit is what survives after it, an optimistic number quietly sets up a loss. Lenders and experienced flippers treat this line as the single biggest risk in the whole project, ahead of even the purchase price, because everything downstream — your offer, your financing, your profit — rests on getting it roughly right. The fix is to build the figure from a written scope of work rather than a gut estimate: walk the property room by room, list what each space needs, and price the big-ticket systems first. Roof, foundation, HVAC, electrical, plumbing and windows dwarf the cosmetic items, so they deserve the most attention and the firmest numbers.

It helps to separate two kinds of work. Cosmetic jobs — paint, flooring, fixtures, landscaping — are fairly predictable and rarely the reason a flip fails. Structural and systems work is where budgets blow up, because problems hide behind walls and under floors until demolition exposes them. Get real contractor bids on the major items before you are locked in, not after, and read the inspection with a skeptic's eye. Order the work sensibly, too — systems and structural repairs come before finishes, so you are not tearing out new drywall to reach old wiring. Then add a contingency, commonly in the range of ten to twenty percent of the rehab, specifically for the surprises that surface once the work begins; a budget with no cushion is a budget waiting to be broken.

Finally, tie the scope back to the after-repair value. Over-improving is a real trap: finishes that outclass the neighborhood cost money the resale comps will never return, so match the quality to what buyers in that area actually expect. Padding the timeline matters as much as padding the budget, because every extra month adds holding costs that the ARV never repays. It is also wise to carry a Plan B before you commit: if the finished house is slow to sell, could you rent it and hold instead? Running the numbers as a rental — a quick cap rate check — tells you whether that fallback works. A rehab budget you can trust is conservative on cost, honest about the difference between cosmetic and structural work, and paired with an exit you can live with if the market shifts.