How this calculator works
The Debt Service Coverage Ratio is the single number DSCR lenders underwrite against:
DSCR = Gross Monthly Rent ÷ PITIA
PITIA is principal + interest + taxes + insurance + association dues (plus mortgage insurance, if the program requires it). The ratio answers one question: for every dollar of mortgage payment, how many dollars of rent arrive?
The approval tiers
| DSCR range | Typical lender outcome |
|---|
| Below 1.00 | Unlikely approval. The property loses money monthly; most lenders decline or force a restructure. |
| 1.00 to 1.24 | Tier-2 pricing. Approvable with a higher rate, reduced LTV (70-75%), and 6+ months of reserves. |
| 1.25 and above | Prime investor rate. Best pricing, up to 80% LTV, easiest approval. |
| 1.50 and above | Some lenders offer rate discounts or waive reserve requirements. |
Why 1.25 is the number that matters
A 1.25 DSCR means rent exceeds the payment by 25%, a cushion that absorbs a vacancy, a missed month, or a repair without the loan going underwater. It is the threshold where lenders’ risk models shift from “conditional approval with pricing penalties” to “clean approval at the best rate.”
The 75% convention trap
Some lenders underwrite at 75-85% of gross rent instead of 100% to model vacancy. The same property can be a 1.30 DSCR at one lender and a 0.98 at another purely because of this convention. The calculator shows both figures so you can pre-screen against either standard before you apply.
Worked example
A fourplex grossing $3,900 per month with a $232,500 loan at 7.5%: principal and interest are about $1,625, taxes $420, insurance $180, for a PITIA of $2,225. DSCR = $3,900 ÷ $2,225 = 1.75. That is prime tier: expect the best rate, 80% LTV availability, and minimal reserves. If the appraiser’s rent schedule instead comes in at $3,400, the DSCR drops to 1.53, still prime but with less cushion. This is why verifying rents before ordering an appraisal matters.
Assumptions and limitations
- The ratio uses gross rent, matching most DSCR programs. Programs that net out vacancy or management will produce a lower ratio; the 75% figure below the breakdown approximates them.
- Enter the full PITIA, including HOA dues and any mortgage insurance. Leaving out a line item overstates your ratio.
- Tier thresholds are industry conventions, not a guarantee. Each lender sets its own cutoffs, LTV caps, reserve requirements, and prepayment penalties; treat the output as a pre-screen, not an approval.
For the full product guide, including 2026 guidelines on down payments, credit scores, reserves, and prepayment penalties, read What is a DSCR loan?. If the numbers are tight, the guide to portfolio lenders covers the main alternative.