The chain, and where it breaks
The structure is simple to describe. Buy something below what it will be worth finished, pay for the work, get it rented, then refinance against the finished value and take out enough to repay the capital you put in. What remains is a property you own with little or none of your own money still committed.
Every step is arithmetic except one. The after-repair value is a prediction about what an appraiser will conclude months from now, based on sales of comparable properties that have not all happened yet. The rehab budget does not determine it. What you spent does not determine it. If the comparables come in soft, the loan is smaller, the proceeds are smaller, and the money you expected back stays in the building.
That is why this page includes the appraisal sensitivity table rather than a single answer. A plan that survives the entered value and collapses at five percent below it is not a plan with a margin, it is a forecast with a decimal point.
Cash left in, and the zero case handled honestly
Cash left in the deal is total cash invested minus refinance proceeds. Proceeds are the new loan minus whatever acquisition debt has to be paid off minus the refinance closing costs, which are real and get forgotten with some regularity.
If the proceeds equal or exceed what you put in, cash left in is zero or negative, and at that point the usual return calculation stops working. Annual cash flow divided by zero is not a large return. It is not a return at all — the expression has no value. Calculators that print "infinite" here, or a percentage in the thousands because the denominator rounded to a cent, are producing an artefact of the arithmetic rather than a fact about the property.
What can be said in that situation is concrete and worth saying: the cash flow in dollars, the equity remaining in dollars, and that your capital is back and free to be used elsewhere. Also worth saying is the cost of getting there, which is a larger loan against the property than a more conservative refinance would leave. A bigger loan means a bigger payment, less headroom against a rent decline, and a thinner equity cushion if values move down. The stress test is the place to see what that does to the monthly numbers.
The costs that get left out
Four lines go missing from these projections more often than any others, and together they routinely account for a fifth of the real capital requirement.
| Line | Why it disappears |
|---|---|
| Holding costs during the work | Payments, taxes, insurance and utilities on a property producing nothing. Two months longer than planned is normal and it is expensive. |
| Refinance closing costs | They come straight off the proceeds, so they turn into cash left in dollar for dollar. |
| Rehab overrun | Opening walls reveals things. A contingency belongs in the rehab figure rather than in optimism. |
| The gap before the first tenant | Finished is not rented. Make-ready, listing and screening take weeks after the work ends. |
Enter these honestly and the project looks worse, which is the correct outcome, because they will be paid whether or not they were entered. Once the property is stabilised, the reserve calculator gives you the monthly cash flow figure this page asks for, built from the actual components rather than a guess.
The part that is not arithmetic
This page deliberately says nothing about what any lender will do. Loan-to-value limits, how long a property must be held before a refinance is available, what documentation is required, what rate applies to a property that is not owner-occupied, and whether a given program exists at all vary by lender, by program, by property type, by state and over time. Any figure printed here as a general rule would be wrong for someone reading it.
The practical consequence is that the terms need to be confirmed in writing with a specific lender before you buy something whose plan depends on them. A refinance that does not materialise leaves the project financed by whatever was used to acquire it, which for short-term acquisition debt is a genuinely difficult position. Ask for the terms first, then use this page. And keep the tax questions — how the rehab is treated, what is capitalised, what any of it means on a later sale — with a CPA, since the answers are federal-plus-state, situation-specific and not something to infer from a calculator.
Questions people ask
What if the refinance returns everything I put in?
Then cash left in is zero and the cash-on-cash return is undefined rather than infinite, which is a real mathematical distinction and not pedantry. There is no denominator, so there is no percentage. This page says so explicitly instead of printing a number, and reports what can be reported: dollars of cash flow, dollars of equity, and the fact that your capital is available again. The position is not free of cost either — it carries the largest loan the structure allows, which means the smallest buffer against a rent decline or a value decline. Being clear about that trade is more useful than a percentage that does not exist.
How should I estimate the after-repair value?
From sales of genuinely comparable finished properties nearby, ideally recent ones, and preferably with input from someone who values property in that specific market for a living. What it should not come from is your purchase price plus your rehab budget plus a margin, which is a calculation about your spending rather than about the market. The appraiser will be looking at comparables and so should you. Then move the figure down in the sensitivity table and see whether the plan still works, because the estimate will be wrong by some amount and the only question is whether the plan survives it.
Do I need to include the acquisition loan?
Yes, if there is one, because the refinance has to pay it off before anything reaches you. Enter the balance that will be outstanding at the refinance, not the original amount, if the two differ. If you bought with cash, leave it at zero and your cash in equals the whole project cost. The distinction matters a lot to the proceeds line: the same new loan produces very different cash back depending on how much existing debt it has to clear first.
Why do the refinance closing costs matter so much?
Because they come off the top of the proceeds, so every dollar of them becomes a dollar of cash left in the deal. On a project where the plan is to get all the capital out, closing costs are frequently the difference between succeeding and leaving several thousand dollars behind. They are also easy to underestimate, since a refinance carries its own set of charges that vary by lender and by state. Ask for an itemised estimate rather than using a percentage from a calculator, including this one.
Is leaving nothing in the deal the goal?
This page does not have a goal and neither should a calculator. Pulling all the capital out means the maximum loan against the property, which means the highest payment, the least room before cash flow turns negative, and the smallest equity cushion if values fall. Leaving some capital in means a smaller loan, more monthly headroom and less money available for anything else. Those are trade-offs with real consequences in both directions, and which side of them suits you depends on your circumstances rather than on a rule. Run both versions through the stress test and compare the months, not the slogans.