How to calculate DSCR, step by step
- Find the monthly rent. Use the current lease, or the market rent from the appraisal's rent schedule. For a 2–4 unit property, add the rent from every unit.
- Add up the monthly PITIA. Principal and interest on the proposed loan, plus monthly property taxes, insurance and any HOA dues.
- Divide the rent by the PITIA. The result is the DSCR.
- Compare the result with the program's minimum ratio. Minimums vary by lender and program.
DSCR -- Debt Service Coverage Ratio -- is the single most important number in investment property lending. Understanding how to calculate it correctly, which inputs to use, and what can go wrong is essential before you submit a deal or make an offer on a property.
Watch: How DSCR is calculated
Video key takeaways
DSCR compares the property's monthly gross rent with monthly PITIA: principal, interest, taxes, insurance, and any HOA dues. A ratio above 1.00 means rent exceeds the housing payment. The final underwriting calculation depends on documented rent and confirmed expenses, so an early estimate is a screening tool rather than a loan approval.
The DSCR Formula
The formula is straightforward:
DSCR = Monthly Gross Rent / Monthly PITIA
PITIA = Principal + Interest + Taxes + Insurance + HOA (if applicable). The result tells you how many times over the rental income covers the housing cost. 1.0 = break even. 1.25 = rent is 25% higher than the payment.
Example: A Tampa rental generates $2,200/month. PITIA is $1,700. DSCR = 2,200 / 1,700 = 1.29. This property qualifies at most lenders.
Rental property DSCR vs. commercial DSCR
Residential DSCR loans on rental property typically divide gross monthly rent by monthly PITIA, as in the formula above, without subtracting operating expenses such as management, maintenance or vacancy. Commercial lending typically divides net operating income, which is income after operating expenses, by annual debt service. Because the two methods use different inputs, the same property can show different ratios, so check which method a program uses before comparing numbers.
DSCR Inputs -- What to Use
Each input in the DSCR calculation requires careful sourcing:
- Monthly rent: Use actual signed lease rent (if occupied) or appraiser market rent opinion (if vacant). For STR, use 12-month average or market rent -- whichever the lender specifies. Do not use Zillow estimates alone -- the appraisal will determine the final number.
- Principal and Interest: Calculate from your expected loan amount and rate. Use a mortgage calculator. Remember that the loan amount at 80% LTV on a $350,000 property is $280,000 -- not $350,000.
- Taxes: Use actual property tax records -- not your home state as a reference. Florida has higher property taxes in some counties than Ohio. The county assessor website shows current tax bills.
- Insurance: Get an actual quote -- do not estimate. Florida insurance costs have increased dramatically. What you assume might be $150/month could be $400/month in a coastal market. This single input can make or break Florida DSCR deals.
- HOA: Check with the HOA directly. Some HOA fees are monthly, some quarterly, some annually. Confirm the exact amount and frequency.
Common DSCR Calculation Mistakes
These errors consistently produce inflated DSCR calculations that fail at underwriting:
- Using asking rent instead of market rent: A seller may be marketing a property at above-market rent. The appraiser will use market comps, not the current lease. If market rent is $200 less, your DSCR drops accordingly.
- Underestimating insurance in Florida: The most common error in Florida deals. Always get a quote from an actual Florida insurer before running DSCR on any Florida property.
- Forgetting HOA: A $500/month HOA fee on a condo can drop DSCR from 1.15 to 0.82 instantly.
- Using list price instead of purchase price: If you are buying at a discount, use your actual purchase price for the loan amount calculation -- not the list price.
- Using wrong LTV: At 75% LTV on a $300,000 property, the loan is $225,000. At 80% LTV it is $240,000. A $15,000 difference in loan amount changes PITIA by $85-100/month.
DSCR Thresholds and What They Mean
DSCR ratios affect rate pricing and program availability:
| DSCR Range | Program Status | Rate Impact |
|---|---|---|
| 1.35+ | Best available programs | Best rate tier |
| 1.25-1.34 | All standard programs | Good rate pricing |
| 1.10-1.24 | Standard programs | Slight premium |
| 1.00-1.09 | Most programs | Moderate premium |
| 0.75-0.99 | Limited programs | Significant premium, more down |
| Below 0.75 | Very limited | Hard to finance |
Use the Free DSCR Calculator
Viador Partners provides a free DSCR calculator at viadorpartners.com/dscr-calculator that calculates:
- DSCR ratio based on your inputs
- Monthly cash flow (positive or negative)
- Annual cash-on-cash return
- Cap rate
- 5-year projection
Run your numbers before submitting a deal. Knowing your DSCR in advance lets you negotiate from knowledge and prevents surprises at underwriting.
Frequently Asked Questions
A DSCR of 1.25 or higher is considered good and qualifies for the best rate pricing. A DSCR of 1.0 is the minimum for most programs. Below 1.0 DSCR programs exist but require higher down payments and carry higher rates. The higher the DSCR, the better the loan terms.
For a duplex, add the rents from both units together and divide by the single monthly PITIA payment for the entire property. Example: Unit 1 rents for $1,400, Unit 2 rents for $1,300. Total rent = $2,700. PITIA = $1,900. DSCR = 2,700 / 1,900 = 1.42.
DSCR uses gross rent -- the full monthly rent before any expenses such as property management fees, maintenance, or vacancy. Expenses are not subtracted in the DSCR calculation. The PITIA payment is the only denominator -- all operating expenses are separate.
Yes -- and you should. Estimating DSCR before making an offer helps you know whether a deal is likely to qualify. Use market rent from Zillow or a local property manager as an estimate, get an actual insurance quote, and use a mortgage calculator for PITIA. Then use our free DSCR calculator. The appraisal will confirm or adjust these inputs.
A DSCR below 1.0 means the property generates less rental income than the monthly payment. Some lenders offer below-1.0 DSCR programs (sometimes called no-ratio or sub-1.0 DSCR) requiring 25-30% down payment and higher rates. Alternatively, increasing the down payment reduces PITIA and improves DSCR. Submit your deal -- there may be structuring options.
PITIA stands for principal, interest, taxes, insurance and association dues. In a DSCR calculation it is the monthly total of the principal and interest on the loan, the monthly share of property taxes and insurance premiums, and any HOA or condo association dues. Operating costs such as property management, maintenance, utilities and vacancy are not part of PITIA.