DSCR Calculator: What Lenders Count, and What They Leave Out

Introduction

There are two DSCR figures for every rental property, and they are not close together. Your lender computes one. The property lives by the other.

TL;DR: Most DSCR lenders take gross rent and subtract only taxes, insurance and HOA. They do not deduct management, maintenance, capital reserves or vacancy. That makes the quoted ratio structurally higher than reality — a property can clear 1.25 at underwriting and still lose money every month. This calculator shows both.

What DSCR actually measures

Debt service coverage ratio is net operating income divided by annual debt service. Above 1.0, the property covers its own loan payment. Below 1.0, something else has to.

DSCR = Net Operating Income
       ÷ Annual Debt Service

Written out in the terms a lender uses:

DSCR = (Gross annual rent − taxes − insurance − HOA) ÷ (annual principal + interest)

And in the terms a prudent investor should use:

DSCR = (Gross annual rent − taxes − insurance − HOA − management − maintenance − reserves − vacancy) ÷ (annual principal + interest)

Same ratio, same property, two different numerators. The gap between them is the whole story.

Why the two numbers differ so much

A DSCR loan qualifies the property rather than the borrower, which is precisely why it has become the default route for investors whose tax returns understate their buying power. But qualifying the property means the lender needs a standardised, verifiable numerator. Taxes come from the county. Insurance comes from a binder. HOA comes from the association.

Management, maintenance, capex and vacancy come from nowhere verifiable. They are estimates. So most lenders leave them out — not because they think those costs are zero, but because they cannot underwrite an estimate you supplied.

That is defensible from the lender's side. It becomes a problem when the borrower reads the lender's ratio as a statement about the deal.

A worked example

Take the calculator's defaults: a $325,000 property, 25% down, 7.75% over 30 years, renting for $2,650 a month. Taxes $4,200, insurance $2,100, no HOA.

The loan is $243,750. Annual debt service is $20,955.

The lender's arithmetic:

• Gross annual rent: $31,800
• Less taxes and insurance: −$6,300
• NOI: $25,500
• DSCR: 25,500 ÷ 20,955 = 1.22

Just under a typical 1.25 threshold. Tight, but many lenders will price it.

The property's arithmetic. Add 8% management, 7% maintenance, 7% capital reserve and 6% vacancy — 28% of rent, or $8,904 a year:

• NOI: $25,500 − $8,904 = $16,596
• DSCR: 16,596 ÷ 20,955 = 0.79

The same property, on the same day, at the same rent. The lender sees 1.22. The property covers 79% of its own debt service.

Neither number is wrong. They answer different questions. The lender's question is "will this loan probably perform?" Yours is "will this property pay me?"

What lenders actually require

Thresholds move with the market and with the lender, but the shape is consistent:

Lender DSCR	Typical treatment
1.25 and above	Standard pricing, widest lender selection
1.15 – 1.25	Available, usually with a rate premium or larger down payment
1.00 – 1.15	Narrower field, expect pricing adjustments and reserve requirements
Below 1.00	Some lenders will still lend on strong ARV or borrower reserves, at a cost

Two things worth knowing. First, the ratio is computed on the loan you are asking for, so raising the down payment raises the ratio — which is how a 1.10 deal becomes a 1.30 deal without the property changing. Second, most lenders will use a market rent estimate from the appraisal rather than your lease if the lease looks high.

For current requirements and pricing, see DSCR loan requirements and what investors are actually paying.

How to use the two ratios together

Use the lender ratio to answer a financing question: will this qualify, at what leverage, and what rent do I need for the threshold? The calculator reports the rent required to hit 1.25 directly.

Use the all-costs ratio to answer an investment question: does this property support itself once it is actually being run? If that number is below 1.0, the deal needs more equity, more rent, or a pass — regardless of what the lender is willing to fund.

The trap is treating a lender approval as a second opinion on the deal. It is not. It is an opinion on the loan.

Where this calculator is deliberately simple

It uses your rent, not an appraiser's. If the appraisal's market rent comes in below your lease, the lender will use theirs. Run it again with their number.

It excludes mortgage insurance and flood. Investment DSCR loans rarely carry PMI, but if yours does, add it to the insurance field.

It assumes a fully amortising loan. Interest-only DSCR loans have lower debt service and therefore a higher ratio during the IO period — and a step up when it ends. Model the post-IO payment, since that is what has to work.

It ignores the interest-rate floor some lenders apply. A few underwrite at a stress rate above your actual rate. If yours does, enter theirs.

FAQ

What DSCR do I need for a DSCR loan?

Most lenders want 1.25 or better for standard pricing. Many will go to 1.00, and some below it with compensating factors — more equity, more reserves, or a strong appraisal. Below 1.00 you are paying for the privilege.

Does DSCR include property management?

Almost never, on the lender's calculation. That is the single biggest reason a lender's ratio and your ratio diverge. Include it in your own analysis whether or not you self-manage — your time has value, and the deal has to survive the day you stop.

Is a higher DSCR always better?

For qualifying, yes. As a measure of the deal, not necessarily: you can lift the ratio simply by putting more cash down, which improves coverage while reducing your return on that cash. A 1.6 DSCR achieved with 45% down may be a worse investment than a 1.25 achieved with 25%. Check cash-on-cash alongside it.

What happens if DSCR falls below 1.0 after closing?

Nothing automatic on most single-property investor loans — there is usually no ongoing covenant, unlike commercial debt. The consequence is practical rather than contractual: you fund the shortfall from somewhere else every month.

Can I improve DSCR without raising rent?

Yes, and it is often faster. Shop the insurance — it is frequently the most overpriced line on the sheet. Appeal the assessment if taxes look high for comparable properties. Extend the amortisation from 25 to 30 years. Or increase the down payment, accepting the trade against cash-on-cash.

Why does my lender's number differ from this calculator?

Most likely one of four things: they used the appraiser's market rent instead of your lease, they underwrote at a stress rate above your quoted rate, they included an escrow line you have not entered, or they are using an interest-only payment. Ask which — the answer tells you how they underwrite.

Conclusion

Run both ratios on every deal. The lender ratio tells you whether the loan closes; the all-costs ratio tells you whether the property pays. When the first clears and the second does not, the deal is not financeable-and-good — it is financeable-and-bad, which is a more expensive mistake than being declined.