What is DSCR?
The debt service coverage ratio asks one question: does this property's income cover its loan payment? It is the lender's central test, and the reason it confuses borrowers is that two different formulas travel under the same name.
DSCR = income ÷ debt obligation. Above 1.00, the income covers the payment with something left over. At exactly 1.00, it covers the payment and nothing else. Below 1.00, the property runs at a shortfall and the difference comes out of your pocket every year.
The complication is that "income" and "debt obligation" each mean two different things depending on who is asking — and the two readings can put the same property on opposite sides of 1.00.
The two formulas
Commercial and agency underwriting divides net operating income by annual debt service. Operating expenses come out of the numerator first, so vacancy, management, repairs and reserves all push the ratio down. This is the version meant when DSCR is discussed as a property metric.
Rental loan programs — the single-family and small-residential products marketed as "DSCR loans" — commonly divide gross rent by PITIA: principal, interest, taxes, insurance and association dues. Nothing is deducted for vacancy, management or maintenance. It is a program convention, not an accounting identity, and it exists because it is fast to underwrite from a lease and a quote rather than from an operating history.
What the difference is worth
Here is one property scored both ways. Same rent, same expenses, same loan — the $600,000 building from the other guides, financed at 25% down and 7.25%.
Scroll the table sideways to see every column.
| One property | NOI ÷ debt serviceCommercial and agency | Gross rent ÷ PITIARental loan programs |
|---|---|---|
| Gross rent | $60,000 | $60,000 |
| Less vacancy | -$3,000 | not deducted |
| Less taxes and insurance | -$9,000 | moved below |
| Less management, repairs, reserves | -$12,000 | not deducted |
| Income used | $36,000 | $60,000 |
| Annual loan payment | $36,838 | $36,838 |
| Plus taxes and insurance | already deducted | $9,000 |
| Obligation used | $36,838 | $45,838 |
| DSCR | 0.98 | 1.31 |
One method says the property does not quite cover its debt. The other says it clears its obligation comfortably. Neither is doing anything improper: they are measuring different things and both report honestly what they measure.
The gap is not a rounding difference or a matter of emphasis. It is the cost of running the building — vacancy, management, repairs and reserves — appearing in one calculation and not the other. Those costs do not stop existing because a formula omits them. They simply stop being the lender's problem and stay yours.
Which one applies to you
Whichever one your lender uses, and you should ask rather than assume. A borrower who runs the commercial formula and concludes the deal is hopeless may be looking at a loan they would get; a borrower who runs the program formula and relaxes may be looking at a property that will not feed itself.
The calculator on this site implements both and makes you choose, for exactly this reason. It does not pick one for you, because being handed the wrong one is how a borrower arrives at an underwriting surprise.
What counts as a passing ratio
There is no single answer, and anywhere that quotes one is describing a particular program at a particular moment. Published minimums vary by loan type and by tier — Fannie Mae's multifamily standards, for instance, set DSCR requirements per mortgage loan type through its underwriting guide rather than as one figure. Single-family DSCR loan products are non-agency programs whose thresholds each lender sets, and moves as the rate environment moves.
So the useful number is the one in your term sheet. Enter it in the calculator and measure against that, rather than against a figure from an article.
What is worth understanding is the shape of the thing. A ratio of exactly 1.00 describes a property with no margin at all: one vacancy, one insurance renewal or one water heater puts it underwater for the year. Whatever minimum a lender sets above 1.00 is buying a cushion, and the cushion is for the same events your own reserves are for.
The three levers when it comes up short
A ratio below the threshold has exactly three arithmetic fixes, and it is worth knowing which one you are actually pulling:
- Raise the income. Higher rent, lower vacancy, or additional income from the property. Real, but not always available on demand.
- Lower the payment. A longer amortisation, a lower rate, or buying the rate down with points.
- Borrow less. A larger down payment shrinks the payment directly. It also lowers your cash-on-cash return, so this lever trades one number against another.
Interest-only deserves a note of its own. It raises DSCR immediately, because an interest-only payment is smaller than an amortising one on the same balance — that is why some programs offer it. Nothing about the property improved. When the interest-only period ends the payment steps up, the ratio drops back, and the property has to carry it on whatever rent it commands then.
Where DSCR sits among the other numbers
DSCR is a survival measure, not a return measure. It does not tell you whether a deal is worth doing — only whether the income covers the debt. A property can clear a lender's threshold comfortably and still be a poor investment, and a strong investment can fail the test on the financing you were offered.
| The question | The number |
|---|---|
| Does the income cover the loan? | DSCR |
| What does the property yield, ignoring the loan? | Cap rate |
| What does my own cash earn this year? | Cash-on-cash |
Three ways the ratio gets overstated
- Market rent instead of lease rent. Underwriting to what the unit could rent for rather than what it does.
- Taxes and insurance left out of PITIA. They are the T and I. Omitting them lifts the ratio and the lender will not omit them.
- Post-sale taxes ignored. In some places a sale can reset the assessment, so the taxes in the seller's operating statement may not be the taxes you will pay. Ask the local assessor before relying on them.