How to Calculate Your DSCR Ratio Step-by-Step

Before you apply for a DSCR loan, you need to know one number: your Debt Service Coverage Ratio. This single metric determines whether you'll qualify and what rates you'll receive.

Let's break down exactly how to calculate DSCR for any investment property. You can also use our free DSCR calculator to run your numbers instantly.

The DSCR Formula

The calculation is straightforward:

DSCR = Gross Monthly Rental Income / Total Monthly Debt Service (PITIA)

That's it. Divide rent by mortgage payment. But the devil is in the details of what counts for each number.

Understanding the Numerator: Rental Income

For Properties with Existing Leases

If you have a signed lease, most lenders use the actual lease amount:

Current monthly rent from lease agreement
Include all units for multi-family
Don't include utilities paid by tenants

For Vacant Properties

If there's no lease, lenders use market rent from the appraisal:

Appraiser researches comparable rentals
Provides opinion of fair market rent
May be conservative compared to actual potential

For Short-Term Rentals

Some lenders accept projected STR income:

Based on AirDNA or similar data
Often use 75% of projected annual income / 12
Not all lenders accept STR income

Understanding the Denominator: PITIA

PITIA stands for:

P - Principal

The portion of your payment that reduces the loan balance.

I - Interest

The cost of borrowing the money.

T - Taxes

Annual property taxes divided by 12.

I - Insurance

Annual hazard insurance divided by 12. May also include:

Flood insurance (if required)
Landlord/rental dwelling policy

A - Association Dues

Monthly HOA or condo fees, if applicable.

Important: PITIA does NOT typically include:

Property management fees
Maintenance reserves
Utilities
Vacancy allowance

Step-by-Step Calculation Example

Let's calculate DSCR for a single-family rental:

Property Details

Purchase price: $400,000
Down payment: $100,000 (25%)
Loan amount: $300,000
Interest rate: 7.75%
Loan term: 30 years
Monthly rent: $3,200

Step 1: Calculate Monthly P&I

Using a mortgage calculator:

Loan: $300,000
Rate: 7.75%
Term: 30 years
Monthly P&I: $2,147

Step 2: Add Monthly Taxes

Annual property tax: $4,800
Monthly taxes: $400

Step 3: Add Monthly Insurance

Annual insurance: $1,800
Monthly insurance: $150

Step 4: Add Association Dues

No HOA for this property
Monthly HOA: $0

Step 5: Calculate Total PITIA

$2,147 + $400 + $150 + $0 = $2,697

Step 6: Calculate DSCR

DSCR = $3,200 / $2,697 = 1.19

This property has a DSCR of 1.19, meaning it generates 19% more income than needed to cover the mortgage.

DSCR Calculations for Different Property Types

Multi-Family Example (Duplex)

Property Details:

Purchase price: $500,000
Loan amount: $375,000 (25% down)
Rate: 8%
Unit A rent: $1,800
Unit B rent: $1,650
Total rent: $3,450

PITIA Calculation:

P&I: $2,752
Taxes: $520
Insurance: $200
Total PITIA: $3,472

DSCR = $3,450 / $3,472 = 0.99

This duplex is just under 1.0 DSCR. To qualify with most lenders, you'd need to either:

Increase rent slightly
Make a larger down payment to reduce P&I
Find a lower rate

Short-Term Rental Example

Property Details:

Purchase price: $350,000
Loan amount: $262,500 (25% down)
Rate: 8.25%
Projected annual STR income: $60,000
Lender uses 75%: $45,000
Monthly income for DSCR: $3,750

PITIA Calculation:

P&I: $1,972
Taxes: $380
Insurance: $250 (higher for STR)
Total PITIA: $2,602

DSCR = $3,750 / $2,602 = 1.44

Strong DSCR due to higher STR income potential.

What DSCR Do You Need?

Lender requirements vary:

DSCR Range	Qualification Status
1.25+	Qualifies easily with best rates
1.10-1.24	Qualifies with standard rates
1.00-1.09	Qualifies with some lenders
0.75-0.99	Requires compensating factors
Below 0.75	Difficult to qualify

How to Improve Your DSCR

If your calculation comes up short, here are strategies to improve it:

Increase the Numerator (Rent)

Get a professional rent analysis - Your estimate might be low
Consider furnished rental - Can command 20-30% premium
Add amenities - Washer/dryer, updated appliances
Evaluate STR potential - If lender accepts it
Rent by the room - Higher total rent in some markets

Decrease the Denominator (PITIA)

Larger down payment - Reduces loan amount and P&I
Buy down the rate - Pay points for lower interest
Shop insurance - Get multiple quotes
Appeal property taxes - If assessment seems high
Choose properties without HOA - Eliminates that expense

Common DSCR Calculation Mistakes

Mistake 1: Using Net Rent Instead of Gross

Lenders use gross rent, not net operating income. Don't subtract:

Property management fees
Maintenance
Vacancy allowance
Utilities

Mistake 2: Forgetting Parts of PITIA

Make sure you include ALL components:

Property taxes (check actual, not estimates)
Full insurance cost
HOA/condo fees
Flood insurance if required

Mistake 3: Using Unrealistic Rent

Be honest about market rent. The appraiser will provide their own opinion, and if it's much lower than yours, you might not qualify.

Mistake 4: Not Accounting for Rate Changes

If you're getting an ARM, the lender might qualify you at a higher rate than the initial rate.

Quick DSCR Calculator

Use our free online DSCR calculator for instant results, or estimate manually with this method:

Rule of Thumb: For every $100,000 borrowed at 8%, your monthly P&I is approximately $733.

Quick Estimate:

Loan amount / $100,000 × $733 = estimated P&I
Add 25% for taxes and insurance = estimated PITIA
Monthly rent / estimated PITIA = rough DSCR

Example:

$250,000 loan: 2.5 × $733 = $1,833 P&I
Add 25%: $1,833 × 1.25 = $2,291 PITIA
$2,800 rent: $2,800 / $2,291 = 1.22 DSCR

DSCR for Portfolio Growth

One advantage of DSCR loans: each property qualifies independently. Your overall debt-to-income ratio doesn't matter.

This means you can scale your portfolio indefinitely as long as each individual property meets the DSCR threshold.

When DSCR Doesn't Tell the Whole Story

Remember, DSCR only measures cash flow coverage. It doesn't account for:

Appreciation potential - A property in a growing market might be worth holding even at 1.0 DSCR
Value-add opportunities - Rent might increase after improvements
Tax benefits - Depreciation and interest deductions improve real returns
Equity buildup - Each payment increases your net worth

A property with a 1.0 DSCR (break-even cash flow) can still be an excellent investment.

Ready to Run Your Numbers?

Now that you understand how DSCR works, see if your investment property qualifies. Our quick assessment takes less than 60 seconds.

Calculate Your DSCR Eligibility

Tanner Cook is a licensed mortgage loan originator (NMLS #2090424). This content is for informational purposes only and does not constitute financial advice. Loan approval is subject to credit and property qualification. Equal Housing Lender.