Cash on Cash Return: How to Calculate It (And Why an 8 Cap Isn’t 8%)

Take one building. A million dollars, $80,000 of net operating income, an 8% cap rate. That cap rate is not going to move for the rest of this article.

Depending on how you finance it and how honest the seller's numbers are, your cash on cash return on that exact same deal can land anywhere from 3% to 12%. Same building. Same price. Same 8% cap. And there's one number that decides which of those you actually get. I'll give it to you at the end, and once you know it you can screen deals in about thirty seconds.

Because here's the misconception I run into constantly with people getting into commercial real estate: an 8% cap rate is not an 8% return. Let me show you why.

Same Deal, By the Numbers

8%

Cap rate, unchanged in every scenario

3% to 12%

Where cash on cash actually lands

$12.50

Value created per $1 of NOI at an 8 cap

What a Cap Rate Actually Measures

The formula is net operating income divided by purchase price. That's the whole thing. But three characteristics of that formula are what trip everybody up.

It's unlevered. A cap rate is calculated before any debt exists. No loan, no payment, no lender. So it cannot possibly tell you what you'll earn on the cash you put in, because it doesn't know how much cash you put in.

It's year one only. A cap rate is a snapshot in time. It tells you that on this day, at this rent, with these expenses, the building throws off this much income. It says nothing about next year or year five.

It's a property metric, not your metric. It describes the building. It does not describe your position in the building. Two investors can buy the identical asset at the identical 8 cap and one makes money while the other bleeds.

Why the Industry Uses Cap Rates Anyway

None of that makes cap rates useless. They're just doing a different job than most people think.

A cap rate is a conversion rate. It turns income into value and back again. Every investor looking at a deal brings a different debt structure, a different payment, a different approach. The cap rate strips all of that out so everybody can look at the building itself, as it sits today, and compare it against another building.

And it's the engine behind why this asset class is so powerful. At an 8% cap rate, every single dollar you add to net operating income is worth about $12.50 of value on the exit. At a 7 cap that same dollar is worth about $14.29. At a 9 cap, about $11.11. That's the entire game of buying square footage and selling cap rates.

Compare that to residential, where you add a third bedroom and the comps say it's worth twenty or thirty grand and that's the end of the conversation. In commercial, a dollar of income is a multiple.

So use the cap rate as a pricing tool. Just stop using it as a return.

Four Things a Cap Rate Cannot See

1. Your debt. The cap rate has no idea what rate you're getting, what your amortization looks like, whether there's an interest-only period, or how much leverage you're using. Fifty percent debt and ninety percent debt produce completely different numbers on the same building.

2. Your cash in. Closing costs, capital expenditures, reserves, loan origination fees. You pay the lender for the right to use their money, and none of that shows up in the cap rate. But all of it shows up in your denominator.

3. Whether the net operating income is even real. This is the one we dig into hardest on every deal. Usually it isn't real, and usually not because the seller is lying. They're managing the property themselves so there's no management fee in the numbers. They're not carrying reserves. They happen to be fully leased right now, so there's no vacancy factor, even though the building has historically run at 12%. And nobody volunteers their credit loss.

4. Timing. When does that income actually start, and what rolls in year one? It might be an 8 cap on paper. But if the tenant has six months of rent abatement, it is not an 8 cap the day you buy it.

How to Calculate Cash on Cash Return

Before we run the building four ways, let's define the thing we're actually measuring, because this is where most people get it wrong.

Cash on cash return is your annual pre-tax cash flow divided by the total cash you put into the deal. That's the formula. Two numbers, and people botch both of them.

The numerator is not your net operating income. It's your net operating income minus your annual debt service. The money that's actually left after the lender gets paid.

The denominator is not your down payment. It's every dollar that leaves your account to get into the deal. Down payment, closing costs, loan origination fee, up-front capital expenditures, and any reserves you're funding at close.

Here's the worked version on our $1,000,000 building. We're 35% down, so that's $350,000 of equity and a $650,000 loan at 6.5% on a 20-year amortization. That loan costs about $4,850 a month, or roughly $58,200 a year in debt service.

Take the $80,000 of net operating income, subtract the $58,200, and you're left with about $21,800 of annual cash flow. Divide that by the $350,000 you put in and you get 6.24%. On a building priced at an 8% cap rate.

Now widen the denominator to what you really spent. Add 2% closing costs, so $20,000, and $50,000 of up-front capex. Your cash in the deal is $420,000, not $350,000. Same $21,800 of cash flow divided by $420,000 is 5.2%. You didn't change the building, the rent, the expenses, or the cap rate. You just counted honestly.

That gap between 8% and 5.2% is the entire point of this article, and every scenario below is just a different version of it.

The Same Building, Underwritten Four Ways

Here's the property. 10,000 square feet, single tenant, $1,000,000 purchase price, so $100 per foot. Rent is $10 a foot on a flat ten-year term with no bumps. Operating expenses are $2 a foot. That's $80,000 of net operating income and an 8% going-in cap rate. I ran every version of this through our Deal Analyzer live, and you can go run it yourself for free.

Pass one, price only. 35% down, 6.5% interest, 20-year amortization. No origination fee, no closing costs, no capex, no reserves. That gives you a 1.38 times debt service coverage ratio, a 10.4% IRR, and a 1.57 times equity multiple over the hold. Year one cash on cash comes in at 6.24%. Not 8%. And honestly, on a ten-year lease with a solid tenant, that's not a bad deal at all.

Pass two, add one interest-only year. I changed nothing else. Same price, same cap rate, same tenant. Year one cash on cash jumps to over 10%. That's a four-point swing from a single line in the loan documents.

Pass three, count every dollar you actually spend. Now we're putting $420,000 of equity in, paying 2% closing costs, which is standard, you'll see anywhere from 1.5% to 2%, and setting aside $50,000 of capex. Because you will spend money on that building. Even if it's in perfect shape you're repainting something or redoing the landscaping, and if the tenant leaves you want cash on hand. Cash on cash drops to roughly 5.2%. Put the interest-only year back on and it climbs to 9.2%.

Pass four, scrub the seller's net operating income. I added a 5% property management fee and 40 cents a foot of capital reserves. That's it, and 40 cents is not a lot. Without the interest-only period, we land at 7.7%.

Same building. Same $80,000 of income the seller reported. Same 8% cap rate on every single one of those passes, and the cash on cash swung all over the place. That's why the cap rate is a great way to compare deals side by side and a terrible way to predict whether a deal cash flows.

One clean reference point: if you pay all cash, with no closing costs and nothing else to get in, an 8% cap rate really will get you very close to an 8% cash on cash return. Add reserves and you'll drift down a little. The moment you add debt, all bets are off.

The Cheat Code Is Your Loan Constant

This is the number I teased at the top, and it's the fastest screen I know of.

Your loan constant is annual debt service divided by the loan amount. That's it. And the reason it matters is that a 6.5% interest rate does not mean you're paying 6.5% a year. Interest is only half the payment. You're paying back principal too.

On that same loan, 6.5% interest on a 20-year amortization, what you actually pay out every year is 8.95% of the loan balance. Which is above an 8% cap rate. That is negative leverage, and a deal with negative leverage is losing money on every borrowed dollar. The debt is costing you more than the building is producing.

The Loan Constant Gap

6.50%

The interest rate you were quoted

8.95%

What you actually pay annually

8.00%

What the building produces

So compare your loan constant to your going-in cap rate before you do anything else. If the constant is higher, you either need to put more cash down to widen the spread, restructure the debt, or walk. Our CRE calculators will get you the constant in a few seconds.

How Much Spread You Actually Need

Here are the two rules of thumb I use. They're rules of thumb, so they won't be perfect in every situation, and both assume a 20-year amortization.

One and a half points above your interest rate gets you to roughly a 1.25 times debt service coverage ratio. That means the deal is financeable. A lender will write the loan. It does not mean you're making any money.

Three points above your interest rate is where it actually starts cash flowing enough to make sense. So on a 6.5% rate, you need at least an 8% cap just to fund the thing, and closer to a 9.5% cap for it to genuinely work.

And you're probably thinking, when have I ever seen a 9.5% cap deal worth buying? Fair. Most of them aren't. There's always a reason a deal is priced at a 9.5 cap, and it's usually a reason to pass. I wrote about that at length in why that high cap rate deal might be a trap.

But that's exactly the point, and it's where this whole thing resolves. You don't go find a 9.5% cap deal. You buy at an 8 and you build your way to a 9.5. A couple of vacant suites you can lease up. Tenants sitting under market rent. Operational efficiencies. Renegotiating existing leases. If you can push in-place income to a 9.5% cap on your basis, the deal works. That's value-add investing in one sentence, and it's why chasing a high going-in cap rate is the wrong hunt.

Which is the real lesson here. The cap rate tells you what you're buying. Your debt structure tells you what you'll earn. And the only way to know which deals belong in which bucket is to run a full underwriting process on anything you're seriously considering.

What Is a Good Cash on Cash Return?

Search this question and you'll get a range, usually 8% to 12%. That number is close to useless on its own, because it ignores the two things that actually determine whether your return is any good: what you paid for the income, and what your debt costs.

Here's the test I actually use. Compare your cash on cash to the going-in cap rate. Remember, if you paid all cash for an 8 cap you'd earn roughly 8%. So if you add debt and your cash on cash comes in below 8%, your leverage is working against you. That's not a good return, no matter what a list on the internet says. That's negative leverage wearing a disguise.

On our building, all cash gets you about 8%. Thirty-five percent down with real closing costs and capex got us 5.2%. The debt made the deal worse. Leverage is only doing its job when it pushes your cash on cash above the cap rate, and that only happens when your loan constant is below it.

So instead of a target number, here's what I want to see on a deal:

Cash on cash comfortably above the going-in cap rate in year one. If it's below, the debt structure is wrong or the price is.

A debt service coverage ratio of at least 1.25 times. Below that and most lenders won't write it anyway.

A real path to push the net operating income. Because year one is not the whole story. A deal that starts at 6% with vacant suites to lease and below-market rents rolling is a better deal than a flat 9% with nowhere to go. One of those compounds and one of those is already finished.

That last point is why I'd rather teach the loan constant than a benchmark percentage. A benchmark tells you how you compare to strangers. The loan constant tells you whether this specific deal, with this specific debt, is going to pay you.

Key Takeaways

Cash on cash return is cash flow over cash invested. Net operating income minus annual debt service, divided by every dollar you put in. Not NOI, and not just your down payment.

A cap rate is unlevered, year one, and property level. It is calculated before any debt exists, so it cannot tell you what you will earn. It describes the building, not your position in the building.

The same 8% cap paid 6.24%, 5.2%, 9.2%, and 7.7%. One interest-only year, real closing costs, $50,000 of capex, a management fee, and 40 cents a foot of reserves. Nothing about the building changed.

Assume the seller's NOI is missing something. Usually a management fee, reserves, a real vacancy factor, or credit loss. Rent abatement in year one can turn a paper 8 cap into something else entirely.

Compare your loan constant to your cap rate first. Annual debt service over loan amount. A 6.5% rate on a 20-year amortization is really 8.95%, and if that is above your cap rate you have negative leverage.

A good cash on cash return is one that beats the cap rate. Forget the 8% to 12% ranges online. If your levered return is below what all cash would have paid, the debt is working against you.

Buy at an 8 and build to a 9.5. You need about three points over your interest rate for a deal to genuinely cash flow. Get there with lease-up, below-market rents, and operations.

This article is adapted from Office Hours on the Tyler Cauble YouTube channel, where I underwrote this deal live. We go live every Tuesday at 8:30am Central. And no, I am not a CPA, so take the tax commentary to yours.

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