How to Calculate DSCR: Step-by-Step Formula with Examples
How to Calculate DSCR: Step-by-Step Formula with Examples
The Debt Service Coverage Ratio (DSCR) is the single most important metric for DSCR loan qualification. Understanding exactly how lenders calculate it — and how to optimize it — can mean the difference between qualifying and not qualifying for your next investment property loan.
The DSCR Formula
DSCR = Gross Monthly Rental Income ÷ Monthly Debt Service (PITIA)
Where PITIA = Principal + Interest + Taxes + Insurance + HOA (if applicable)
What Counts as Rental Income?
For DSCR calculation purposes, lenders use the lesser of:
- The actual lease amount (if the property is currently rented)
- The market rent from a third-party appraisal (Form 1007 for SFR, Form 1025 for 2-4 units)
Short-term rental (STR) income: Some lenders accept STR income (Airbnb/VRBO) using 12–24 months of documented rental history. The qualifying income is typically 75–90% of the gross STR revenue to account for vacancy and platform fees.
Vacancy factor: Most lenders do NOT apply a vacancy factor to the gross rent for DSCR calculation purposes (unlike traditional income property underwriting). The full market rent is used.
What Counts as Debt Service?
The monthly debt service includes:
- Principal & Interest (P&I): The mortgage payment based on the loan amount, rate, and term
- Property taxes (T): Annual taxes ÷ 12
- Homeowner's insurance (I): Annual premium ÷ 12
- HOA dues (A): Monthly HOA fee if applicable
- Flood insurance: If required by lender
What is NOT included: Property management fees, maintenance reserves, capital expenditures, utilities. These affect your actual cash flow but not the DSCR calculation.
Step-by-Step DSCR Calculation Examples
Example 1: Single-Family Home (Phoenix, AZ)
| Item | Amount |
|---|---|
| Purchase price | $350,000 |
| Down payment (20%) | $70,000 |
| Loan amount | $280,000 |
| Interest rate | 7.25% (30-year fixed) |
| Monthly P&I | $1,910 |
| Monthly property taxes | $290 |
| Monthly insurance | $120 |
| Monthly HOA | $0 |
| Monthly PITIA | $2,320 |
| Market monthly rent | $2,600 |
| DSCR | 2,600 ÷ 2,320 = 1.12 ✓ |
This property qualifies at up to 75% LTV with a DSCR of 1.12.
Example 2: Duplex (Las Vegas, NV)
| Item | Amount |
|---|---|
| Purchase price | $480,000 |
| Down payment (25%) | $120,000 |
| Loan amount | $360,000 |
| Interest rate | 7.50% (30-year fixed) |
| Monthly P&I | $2,519 |
| Monthly property taxes | $380 |
| Monthly insurance | $180 |
| Monthly PITIA | $3,079 |
| Market monthly rent (both units) | $3,400 |
| DSCR | 3,400 ÷ 3,079 = 1.10 ✓ |
Example 3: Below 1.0 DSCR (Still Qualifies)
| Item | Amount |
|---|---|
| Loan amount | $400,000 |
| Monthly PITIA | $3,200 |
| Market monthly rent | $2,800 |
| DSCR | 2,800 ÷ 3,200 = 0.875 |
This property has a DSCR below 1.0 but still qualifies under most programs at up to 65% LTV. The borrower is making up the shortfall from other income or reserves.
How to Improve Your DSCR
If your DSCR is too low to qualify, here are strategies to improve it:
- Increase the down payment — a larger down payment reduces the loan amount and monthly P&I
- Choose interest-only — IO payments are lower than fully amortizing payments
- Buy down the rate — paying points upfront reduces the monthly payment
- Find a higher-rent property — the rent-to-price ratio is the most important factor
- Negotiate lower HOA — HOA fees directly reduce DSCR
Free DSCR Calculator
Use our free DSCR calculator to instantly calculate the DSCR for any property and see which loan programs you qualify for. No email required.
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