How to Estimate DSCR Before Application 2026: Quick Formula and Common Errors

Debt service coverage ratio is the metric non-QM lenders use to determine whether a rental property generates enough income to support the mortgage payment. An MLO who can estimate DSCR before submitting a file can pre-screen deals, advise investors on the right loan amount, and avoid sending deals that will come back as declines.

The Basic DSCR Formula

DSCR equals gross rental income divided by PITIA (principal, interest, taxes, insurance, and HOA dues). A DSCR of 1.0 means the rental income exactly covers the payment. A DSCR of 1.25 means the property generates 25 percent more income than the payment requires. Most DSCR lenders require 1.0 at standard LTV and allow below 1.0 at reduced LTV with higher FICO requirements.

Common Errors in DSCR Estimation

• ✦Using vacancy-adjusted income: most DSCR lenders use gross scheduled rent from a lease or market rent from a 1007 appraisal, not a vacancy-adjusted figure. Using it will produce a lower DSCR estimate than the lender will calculate.
• ✦Forgetting HOA: for condos and townhomes with HOA dues, the monthly fee is included in the PITIA denominator. Forgetting it overstates the DSCR.
• ✦Using the wrong property tax figure: estimates from the purchase price may be significantly different from the actual assessed value after transfer. In California, property tax can reset substantially at sale.
• ✦Ignoring the interest rate: the DSCR is calculated against the note rate on the DSCR loan, which may be 75 to 150 basis points higher than agency rates for the same borrower profile.

Pre-Screening Checklist

• ✦Get a signed lease or 1007 market rent estimate before calculating
• ✦Use the actual lender's current rate for the DSCR loan at the applicable LTV and FICO tier
• ✦Include taxes, insurance, and HOA in the denominator
• ✦Run the DSCR at 1.0 to find the maximum loan amount the property can support at market rent