Cash-on-Cash Return for an STR
Cash-on-cash return, a year's cash flow as a share of the total cash you put in, is the clearest answer to "what is my actual cash earning?" But it works only if you count all the cash you put in. Most STR buyers divide by the down payment and quietly forget the furnishing, the closing costs, and the setup, which makes any deal that earns cash look better than it is. Here's how to compute it accurately, and what it can and can't tell you.
Matt NunnFounder, Builders Finance10 min readOn this page5 sections
Key takeaways
- Cash-on-cash return is one fraction: annual pre-tax cash flow after debt service and the capital reserve ÷ total cash invested (that cash flow is NOI minus annual debt service minus the capital reserve). NOI is net operating income, what the property earns after operating costs and before loan payments. Debt service is a year's loan payments, principal and interest, and the capital reserve is money set aside each year to replace things that wear out. Cash-on-cash is the yield your actual out-of-pocket cash is earning this year, nothing more and nothing less.
- The numerator is the realistic cash flow worked out in Estimating STR Revenue Without Fooling Yourself, What STRs Actually Cost to Run and Why Isn't My Airbnb Cash Flowing? The denominator is where the metric is most often distorted, usually by counting only the down payment and forgetting everything else it took to open the doors.
- For a short-term rental, "everything else" is large: closing costs, and especially furnishing and setup, the $30–50k a long-term rental never spends. Leave it out and, on a deal that earns cash, your return can look far better than it is.
- Cash-on-cash is a single-year snapshot. Use year one to see your liquidity (the cash you can get to quickly) and your startup risk: the setup capital is real, and so is the ramp, the slower first year while bookings build. Use a stabilized year, a typical year once that ramp is behind you, to judge the property's long-term earning power. Read both, not just one.
- It's a cash yield, so it deliberately ignores appreciation, loan paydown, and taxes. It answers one question well; it is not your total return, and it is not the same number as cap rate, which is the property's NOI as a share of its price, its yield before any loan.
What cash-on-cash actually measures
It's the yield on the cash you actually put in. The whole metric is a single fraction:
Cash-on-cash return = annual pre-tax cash flow after debt service and the capital reserve ÷ total cash invested
Cash-on-cash answers a much narrower question than what your wealth will do: what cash yield did this deal produce on the cash I actually put in this year? Its usefulness comes entirely from staying inside that question.
The numerator is what the property puts in your pocket in a year after the mortgage is paid: your pre-tax cash flow after debt service and the capital reserve, the last number from the cash-flow guide, Why Isn't My Airbnb Cash Flowing?. The denominator is every dollar of your own money it took to get the property earning. Divide one by the other and you get a percentage you can read like any yield: this is what my cash is earning this year.
That "after the mortgage" part is what makes cash-on-cash different from cap rate, and the difference matters enough to name now. Cap rate measures the property (NOI ÷ price) as if you'd paid cash; it ignores your loan entirely. Cash-on-cash measures you: your cash flow after debt service, over your actual cash in. Put it in one line: cap rate evaluates the property; cash-on-cash evaluates your investment in that property. Same deal, two very different numbers. Start both from the same operating NOI: cap rate stops there, while cash-on-cash carries on, subtracting debt service and the capital reserve and dividing by the cash you actually invested. The distance between them is what financing and your capital structure did to your return. (The full comparison, and when each one misleads, is in Cap Rate for STRs (and Why It Misleads).)
The numerator: realistic cash flow, nothing borrowed from optimism
Whatever's wrong with your cash flow is wrong with your return. The numerator is pre-tax cash flow after debt service and the capital reserve — revenue, minus operating expenses (management included), minus debt service, minus the capital reserve — and it's only as accurate as the revenue and cost work behind it. If the revenue line was a raw comp (an unadjusted comparable listing) and the cost stack was missing half its lines, the cash flow is inflated, and so is every return you compute from it. There's nothing new to do here; it's a reminder that cash-on-cash inherits the accuracy of the numbers above it. (Getting that number right is Estimating STR Revenue Without Fooling Yourself, What STRs Actually Cost to Run and Why Isn't My Airbnb Cash Flowing?)
The denominator: count every dollar, not just the down payment
This is where the metric is won or lost. Total cash invested is all the money that left your accounts to get this property open, and for a short-term rental it is a stack, not a single line. Here it is for the example deal these guides use, an illustration rather than a forecast, whose full assumption set is listed in The Assumptions Behind Every Model:
| Cash you put in | Example deal ($650k) | Usually forgotten? |
|---|---|---|
| Down payment | $162,500 (25%) | No — everyone counts this |
| Closing costs | ~$19,500 (~3%) | Often |
| Furnishing & setup | $45,000 | Almost always |
| Operating reserve / working capital | committed floor only (see below) | Almost always |
| Total cash invested | $227,000 | — |
The down payment is the one number nobody forgets, and on its own it's well short of the real figure. Closing costs are a few percent of price. And furnishing and setup are the line that separates STR math from long-term-rental math entirely: a short-term rental has to be fully furnished, equipped, photographed, and stocked before it earns a dollar, and on a house like this that's tens of thousands of dollars of your own cash. Divide by the down payment alone and you haven't computed a return; you've produced a percentage that only looks like one.
Two wrinkles to get right. First, the cash buffer — not the capital reserve, which is an annual cost already in the numerator: if you're permanently setting aside a cash buffer as the property's working-capital floor, that's committed capital, and it belongs in the denominator. If it's just personal savings you keep liquid and might spend on anything, leave it out. Second, financing the furniture doesn't make it free. Pay cash and the $45,000 sits in the denominator; put it on a furniture loan or a card and it moves to the numerator instead: a new debt-service line that lowers your cash flow. Either way you paid for it. Financing only shifts the weight from one half of the fraction to the other; it never removes it. A return that looks better only because the furniture is out of the denominator isn't better.
What this does to the example deal
The naive and the fully counted returns sit on opposite sides of "worth doing." Take the example deal again, the $650,000 vacation home. Underwritten naively, the buyer sees about $30,080 of cash flow on $162,500 of cash in (the down payment) for a cash-on-cash return of 18.5%. Underwritten realistically — management priced in and the capital reserve set aside — the cash flow after debt service and the capital reserve is about −$25,820 and the cash in is $227,000 once closing and the $45,000 of furnishing are counted, for a cash-on-cash return of −11.4%.
Look at what moved. The numerator collapsed (realistic revenue, the full cost stack, management and the reserve took $30,080 down to about −$25,820), and the denominator grew by nearly $65,000 (the money the naive version pretended it never spent). Cash-on-cash was distorted from both ends at once, which is exactly why it's such a useful discipline: it makes you get the numerator and the denominator right at the same time, so a deal can't hide in either one.
What cash-on-cash tells you — and what it doesn't
It answers one question cleanly, and stays silent on three others. Cash-on-cash is a genuine cash yield, which makes it good for the thing yields are good for: comparing the cash efficiency of one deal against another on the same complete basis, or against whatever alternative you'd otherwise do with the money. Used that way it's one of the most practical numbers in underwriting.
But it is deliberately blind to three things, and reading it as if it weren't is the trap. It ignores appreciation and loan paydown, real components of return that simply aren't cash in your pocket this year. It ignores taxes: depreciation and deductions can change your after-tax result meaningfully, and how they apply depends on your situation and belongs with your own qualified tax professional. And it ignores time: cash-on-cash is a single-year snapshot, and for an STR the first year is often the weakest it will post, because the setup capital is fully spent while operations are still stabilizing. A deal's year-one reading can look materially different once it stabilizes — though on the example deal the ramp is not what sinks it: about −11.9% in the first year against −11.4% stabilized. So compute it both ways (year one to size the liquidity and startup risk you're taking on, a stabilized year to judge the property's long-term earning power) and read it as one accurate yield among several measures, not as the whole verdict.
Both halves of the fraction get the same treatment as any other number: the four moves of the Builders Finance Underwriting Method that open The STR Deal Underwriting Manual.
A return means nothing until every dollar you put in is in the denominator.
The easiest way to make a bad deal look good is to divide real cash flow by a fraction of the real cash invested. Count the down payment, the closing costs, the furnishing, and the setup, all of it, before you take the return seriously. A return computed against the down payment alone isn't optimistic; it's measuring the wrong thing.
The mistake is dividing by the down payment. It's the most natural error in real-estate math because the down payment is the one big check you consciously write, so it feels like "the money you put in." But the closing costs cleared your account too, and the $45,000 of furniture is sitting in the house. Counting only the down payment doesn't just nudge the return up; on a fully-furnished STR it can materially overstate it, turning a flat deal into an apparently great one. If a return looks strong, check the denominator before you believe it.
Your action plan
- Start with realistic cash flow. Use your stabilized pre-tax cash flow after debt service and the capital reserve — revenue net of fees, the full cost stack with management priced in, the capital reserve and debt service — not a naive or year-one figure.
- Build the full denominator. Down payment + closing costs + furnishing and setup + any reserve you're funding. Every dollar that left your accounts to open the doors.
- Divide, and label it. Cash flow ÷ total cash invested. Write the percentage next to the two numbers that made it, so the inputs travel with the result.
- Do it twice — year one and stabilized. Year one carries the setup drag; the stabilized year shows what the deal actually yields. Judge on the second.
- Compare on the same basis. When you stack this deal against another (or against an alternative use of the cash), make sure both were computed with the full denominator; otherwise you're comparing an accurate number to a flattering one.
- Remember what it leaves out. Before you decide, add back the context cash-on-cash ignores (appreciation, paydown, and, with your tax professional, tax treatment) rather than letting one yield stand in for total return.
The bottom line
Cash-on-cash return is the most useful one-line answer to "is my money working?", but only when both halves of the fraction are accurate. The numerator is only as good as your revenue and cost work; the denominator is yours to get right, and getting it right means counting the furnishing and the closing and the setup alongside the down payment. Do that, compute it for a stabilized year, and read it for what it is (a clean cash yield, not the whole story of the deal), and you'll have a number you can actually compare and actually trust. Divide by the down payment alone and you'll have a number that flatters every deal that earns cash, by a margin that depends on how much you left out, which is the same as telling you nothing.
Educational information only — not individualized tax, legal, or investment advice. The worked example is an illustrative model, not a projection or a recommendation.
