The Quick Read: The combined monthly rent from both units has to equal the full monthly payment (principal, interest, taxes, insurance, and any association dues) multiplied by the ratio the program requires, so a 1.00 floor needs rent equal to the payment and a 1.25 target needs rent 25% above it. That is the whole formula, run in reverse. The hard parts are knowing which rent the lender actually counts and which costs sit inside the payment.
Key takeaways
- Required rent equals PITIA times the target ratio. Both units are added together before the test.
- The lender counts the lower of your lease rent and the appraiser’s market rent, not the rent you hope to charge.
- Taxes, insurance, and dues sit inside the payment, so a high-cost duplex needs more rent than its loan balance suggests.
- Clearing the ratio is not the same as making money. Repairs, vacancy, and management sit outside the test.
DSCR Calculator
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Rate source: Freddie Mac 30-yr average via FRED® — Federal Reserve Bank of St. Louis · effective Oct 15, 2026
Prefilled with starting assumptions — enter your own rent or nightly figures, taxes, insurance, and HOA for a more accurate picture.
Program parameters update from Lendmire’s centralized guideline source. Taxes and insurance are editable estimates.
As of Oct 15, 2026 · General Freddie Mac market benchmark, not a Lendmire loan offer. Rent, nightly rate, occupancy, taxes, and insurance are editable estimates. Short-term rental figures are estimates only and vary significantly by season, property type, management approach, and local short-term-rental rules — confirm local regulations before relying on them. Qualifying income for short-term rentals varies by program — some use appraisal market rent, others use documented STR history or projections — and is confirmed in underwriting. Not a Loan Estimate, approval, or commitment to lend. Program availability and eligibility are subject to lender guidelines, credit approval, property review, and underwriting.
The Rent a Duplex Needs to Cover Its DSCR Loan
Take the monthly payment and multiply it by the ratio the program wants. The answer is the total monthly rent the duplex must show. A DSCR (debt service coverage ratio) is simply monthly rent divided by that payment, so solving for rent just flips the equation.
The payment here is called PITIA: principal, interest, taxes, insurance, and association dues. Add flood insurance if the property sits in a flood zone. The table below shows the required rent as a multiple of PITIA, with each unit’s share if the two units rent for the same amount.
| Target ratio | Total rent needed | Each unit, if equal |
|---|---|---|
| 1.00 | 1.00 × PITIA | 0.50 × PITIA |
| 1.10 | 1.10 × PITIA | 0.55 × PITIA |
| 1.20 | 1.20 × PITIA | 0.60 × PITIA |
| 1.25 | 1.25 × PITIA | 0.625 × PITIA |
Read the ratio this way. At 1.00, rent exactly equals the payment. Above 1.00, rent exceeds the payment and leaves a cushion. Below 1.00, the owner covers the gap from personal funds. This is the general way the debt service coverage ratio is described.
Here is where 1.00 sits in our network. It is where many select programs start, and stronger ratios tend to open better pricing and more leverage. A separate select-lender path takes coverage below 1.00, with leverage and terms adjusted.
A duplex has one real edge. Two rents pay one payment. If one tenant leaves, the other unit still carries part of the load, though the lender’s test uses both units as if they were rented.
What Goes Into the Payment
PITIA is the denominator, so anything that raises it raises the rent you need. Five pieces make up the stack:
- Principal and interest on the loan.
- Property taxes, which vary widely by county.
- Hazard insurance, plus flood coverage where required.
- Association dues, if the duplex sits in a managed community.
- Interest-only periods, which remove principal from the payment.
Many investors size a duplex by its price and loan balance alone. That misses the point. Two duplexes with the same loan can need very different rent because taxes and insurance differ. Get tax and insurance figures early, before you fall in love with a property.
An interest-only period lowers the payment, so the ratio rises mechanically. Interest-only periods and 40-year terms are available through select lenders in our network. The spine of the network is still the 30-year fixed, and ARM structures exist for investors who want them. Which structure fits depends on how long you plan to hold.
Which Rent Counts? (It Is Not the Rent You Expect)
The lender usually counts the lower of two numbers: what the leases say and what the appraiser says the units should rent for. Your pro forma does not enter the test.
For a two-to-four-unit property, the appraiser reports market rent for each unit on Form 1025, the small residential income property appraisal report. The Fannie Mae Selling Guide lists Form 1025 for two- to four-unit properties, and the Fannie Mae forms index confirms the title. Treat that as a form name only. The form is a standard template, and DSCR loans follow their own program rules, not agency rules.
Say PITIA on a duplex is X. Here are three scenarios, all expressed as multiples of X:
| Situation | Rent counted | Ratio |
|---|---|---|
| Leases 1.30X, market 1.10X | 1.10X (lower) | 1.10 |
| Leases 0.95X, market 1.15X | 0.95X (lower) | 0.95 |
| Unit A leased 0.55X, unit B vacant | Program-dependent | Varies |
The first row is the surprise. A tenant paying above market does not lift your ratio. The appraiser’s figure caps it, and a file that looked like 1.30 on paper tests at 1.10.
The second row cuts the other way. If you plan to raise rents after the leases end, the lender still tests the lower lease number. Market rent may carry more weight when the appraisal and rent comparables support it, but that depends on the program.
For the vacant unit, practice varies. A fully vacant duplex is typically tested on market rent alone. A half-leased duplex can be treated unit by unit, with the lease for one unit and market rent for the other. Ask about this before you apply, because programs in the network differ.
How Underwriting Treats Your Duplex, Step by Step
DSCR loans are designed for non-owner-occupied investment properties. Because they are business-purpose investor loans, they are reviewed differently from a standard owner-occupied mortgage. Qualification runs primarily on property-level rental income covering the payment, subject to lender guidelines.
Here is the sequence on a typical file:
1. Build the payment. The lender totals principal, interest, taxes, insurance, and any dues.
2. Establish the rent. Leases for both units are reviewed and compared with the appraiser’s market rent on Form 1025.
3. Divide. Total rent used for lender review is divided by PITIA, and the result is tested against the program’s floor.
4. Price and size the loan. Better ratios tend to earn better terms, and weaker ones can trim leverage.
5. Check the rest of the file. Credit, reserves, and property eligibility are reviewed alongside the ratio.
The appraisal does two jobs at once. It sets value, which drives LTV (loan-to-value, the loan as a percentage of the property’s value). It also sets rent, which drives the ratio. A low rent opinion can sink a file that looked fine on your spreadsheet.
Expect to provide both leases and a rent roll, the appraisal, tax and insurance figures, and an association statement if one applies. If the loan closes in an LLC, entity documents are added, subject to lender program eligibility.
Network Guidelines That Move the Rent Number
Our network is a wholesale group of DSCR lenders, and guidelines differ from one to the next. These ranges are typical, not promises, and every file is underwritten individually. For the full picture, read the complete DSCR loans guide.
Leverage. On a purchase of an investment property, most files land at 75%-80% LTV, which means 20%-25% down. Select high-leverage programs reach 85% LTV with roughly a 700+ score. On a cash-out refinance of an investment property, the ceiling tops out around 75% LTV across most of the network, with about six months of seasoning as the common expectation.
Credit. A 620 floor exists in parts of the network. Most programs want around 660, and 700+ unlocks the strongest leverage tiers.
Reserves. Reserves are cash left over after closing, measured in months of PITIA. They vary by lender, leverage, loan size, and transaction type. About six months is common, conservative rate-and-term files at modest leverage under $1,500,000 can see reserves waived, and larger loans typically step up to about nine months.
Loan size. Standard programs run up to $3,000,000. Above $2,500,000 the network generally holds to 30-year fixed structures.
Coverage floors. As noted, 1.00 is where many select programs start. Coverage below 1.00 is available through select lenders in the network, with leverage and terms adjusted. No-ratio qualification is available only through select lenders, generally for borrowers who already own a primary residence.
A larger down payment lowers the payment and can lift the ratio. It never erases leverage caps, credit floors, reserve rules, or property eligibility. The strongest files clear both tests: enough equity and enough rental coverage.
One practitioner pattern is worth knowing. Files tend to get into trouble not on the math you ran, but on the insurance and tax numbers that arrive later. A duplex that clears the target on your estimate can slip when the real quote lands, so build in a cushion above the minimum.
What Moves the Ratio Most
Not every lever pulls equally. This table ranks the common ones by how directly they change the number.
| Lever | Effect on the ratio | Notes |
|---|---|---|
| Appraiser’s market rent | Direct, large | Sets the numerator |
| Taxes and insurance | Direct, large | Inside PITIA |
| Interest-only period | Raises it mechanically | Select lenders; principal drops out |
| Larger down payment | Raises it, with limits | Does not clear other rules |
| Lower purchase price | Raises it | Shrinks the loan and often taxes |
Here is the honest read on the down payment. It helps most when the ratio is close to the floor. When the shortfall is large, more cash down rarely fixes it, and the real fix is a different property, a different structure, or rents that can move toward market.
DSCR vs. conventional financing
There are two common ways to finance an investment property, and they qualify you differently — here’s how investors weigh them.
Why investors choose it
- Qualifies on the property’s rental income — no personal tax returns, W-2s, or pay stubs needed to document income.
- No personal debt-to-income ceiling to clear, so existing mortgages and obligations don’t cap your borrowing the same way.
- Can be closed in an LLC, keeping the property inside a business entity.
- Built for scaling — not held to the limit on number of financed properties that conventional financing applies.
- Underwriting centers on the deal: generally qualifies when the rent covers the payment, a 1.00x coverage ratio being a common baseline (confirmed in underwriting).
- Designed specifically for investment property, including long-term and, where the program allows, short-term rentals.
Where it’s strong
- Often the lowest ongoing financing cost for a buyer who fully qualifies on personal income — a fit for a first property or a cost-first purchase.
Trade-offs for investors
- Requires full personal income documentation and must fit within a debt-to-income limit — salary, existing debts, and other mortgages all count.
- Typically held in your personal name rather than a business entity.
- Caps how many financed properties you can carry, which can become a ceiling as a portfolio grows.
- Evaluates you as a borrower as much as the property, which usually means more paperwork.
How investors usually choose: a first or single property often optimizes for the lowest financing cost; portfolio builders often optimize for leverage, vesting in an LLC, and scaling past conventional caps. The right answer depends on your goals, the property, and current guidelines — both paths run through select lenders in Lendmire’s wholesale network, with eligibility and terms confirmed in underwriting.
If the Rent Falls Short
A short ratio is a decision, not a dead end. Work through these options in order:
1. Check the numbers again. Confirm the lease totals, the appraisal’s rent opinion, and the tax and insurance inputs.
2. Lower the loan. More down, within the program’s rules, trims the payment.
3. Change the structure. An interest-only period, available through select lenders, can lift the ratio.
4. Look at a sub-1.00 path. Select lenders in the network take coverage below 1.00, with leverage and terms adjusted. Qualification stays subject to lender guidelines, credit approval, and property review.
5. Move to a different duplex. Sometimes the rent-to-price relationship is simply wrong.
A tight deal is a legitimate trade-off, but a thin margin leaves less room for a vacancy or a repair.
The Ratio Is Not Cash Flow
Clearing 1.00 does not mean the duplex makes money. DSCR compares rent to PITIA only. Repairs, vacancy, management, utilities, and capex sit outside the calculation.
Picture a duplex that tests at 1.05. After a few months of vacancy and a roof repair, the owner is writing checks. The loan qualified, but the investment lost money. Run your own cash flow separately from the lender’s test.
Do not confuse this ratio with the commercial version either. Commercial and larger multifamily lending uses net operating income divided by annual debt service, and Wikipedia’s DSCR entry gives 1.25 as a typical commercial minimum. That is a different test with a different numerator. Residential one-to-four-unit DSCR loans generally use gross rent over PITIA.
Tax treatment can depend on how the funds are used and how the property is held; investors should keep clear records and speak with a qualified tax professional before relying on any deduction.
Edge Cases Worth Knowing
Short-term rental duplexes. Income swings more, so programs scrutinize it harder. On a short-term rental purchase, leverage tops out at 75% LTV, with a 640+ score and about 12 months of hosting history expected, and a 1.00 coverage floor. Refinances carry their own terms, with leverage lower than on a standard rental. Seasonal income raises its own questions, which Lendmire’s piece Does a Ski Cabin That Earns One Season Cover Its DSCR Loan Payment? works through. Short-term rental rules can vary by city, county, HOA, and property type, so investors should confirm local rules before relying on projected rental income. Final terms depend on lender guidelines, property type, leverage, and the borrower’s complete credit picture.
Owner-occupied duplexes. If you live in one unit, this is a different product track. DSCR loans are for investment properties you do not occupy.
Unusual structures. Manufactured homes (single- and double-wide), log homes, and barndominiums are not offered in the network’s DSCR programs.
Unequal units. A two-bedroom and a one-bedroom rent for different amounts, and only the sum matters. Do not assume a half-and-half split.
Key Terms Defined
DSCR (debt service coverage ratio): Monthly rent divided by the full monthly payment, used to test whether a rental covers its own debt.
PITIA: Principal, interest, taxes, insurance, and association dues, the full monthly payment the lender tests.
LTV (loan-to-value): The loan balance as a percentage of the property’s value.
Form 1025: The appraisal report for two- to four-unit properties, which includes the appraiser’s market rent for each unit.
Reserves: Cash you hold after closing, counted in months of PITIA.
Interest-only period: A stretch where the payment covers interest but no principal, which raises the ratio.
Frequently Asked Questions
How much rent does a duplex need for break-even coverage?
Rent equal to the full PITIA, with both units added together. At a 1.00 floor the required rent is 1.00 times the payment. Many select programs start there, and stronger ratios tend to open better pricing and leverage.
Do both units count toward the ratio?
Yes. The lender adds the rent used for lender review from both units and divides by one payment. That is why a duplex can clear a ratio that a single-family home with the same loan would miss.
What if one unit is vacant?
It depends on the program. A fully vacant duplex is typically tested on market rent, while a half-leased one may be treated unit by unit. Ask before you apply so the numbers on your spreadsheet match what underwriting will use.
Which rent does the lender use, the lease or the appraisal?
Usually the lower of the two. A lease above market does not raise the ratio, and a lease below market holds it down even if you plan to raise rent later.
Will a bigger down payment fix a short ratio?
It can help when you are close to the floor, since a smaller loan means a smaller payment. It does not lift leverage caps, credit floors, or reserve rules, and it rarely fixes a large shortfall.
If You Want to Test Your Own Duplex
If you are buying or refinancing a rental property and want to see how the numbers work, Lendmire can help you compare DSCR loan options based on the property income, credit profile, leverage, and investor goals. Lendmire is a broker arranging DSCR financing through select lenders in its wholesale network across 41 markets, including Washington, D.C. The estimate in the site calculator is illustrative only, and nothing here is a commitment to lend.
About Lendmire
Lendmire (NMLS# 2371349), a non-QM mortgage broker serving investors in 41 markets including Washington, D.C., helps structure DSCR scenarios commonly evaluated around a property’s rental income rather than personal income paperwork, subject to lender guidelines. A Scotsman Guide Top Mortgage Workplace in 2025 and 2026, Lendmire places loans through wholesale investor lenders and is not a direct lender.
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References
1. Wikipedia: Debt service coverage ratio
3. Fannie Mae Selling and Servicing Guide Forms
This article is part of Lendmire’s DSCR loan program — full qualification details, guidelines, and scenarios live on the program page.
Related reading: How to Qualify for a DSCR Loan in California · How to Qualify for a DSCR Loan in Washington · How to Qualify for a DSCR Loan in Tennessee
Brandon Miller
Founder & CEO, Mortgage Loan Originator, Lendmire LLC
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- Lendmire LLC · Firm NMLS# 2371349 · Verify firm licensure
Important disclosures. Lendmire (NMLS# 2371349) is a licensed mortgage brokerage. Lendmire is not a direct lender, depository institution, or financial advisor. All loan inquiries are subject to lender underwriting; this article does not constitute a commitment to lend. Rates, terms, and program guidelines are subject to change without notice and vary by borrower profile, property type, and state. Information in this article is general in nature and is not financial, legal, or tax advice. Equal Housing Opportunity. NMLS Consumer Access: nmlsconsumeraccess.org.