DSCR Calculator: Ratio, Max Loan and Rent Needed

Two DSCR formulas, and why lenders use different ones

Debt service coverage ratio measures how many times a property's income covers its debt payment. A DSCR of 1.25 means $1.25 of income for every $1.00 of debt.

Residential DSCR loans (the investor mortgages for 1 to 4 unit rentals) usually use DSCR = gross monthly rent ÷ PITIA. PITIA is principal, interest, property taxes, insurance, and association dues. There is no vacancy or repair deduction; the lender builds that cushion into the minimum ratio instead.

Banks and commercial lenders use DSCR = net operating income ÷ annual debt service. NOI subtracts vacancy and all operating costs, including taxes and insurance, and debt service is principal and interest only. The same property scores lower this way. Pick the method your lender uses from the dropdown; lender pages rarely tell you which one they apply.

Worked example: $300,000 loan on a $2,800 rental

Loan $300,000 at 7.5 percent over 30 years: principal and interest is $2,097.64 a month. Add property tax of $300 a month and insurance of $125 and PITIA is $2,522.64.

DSCR = $2,800 ÷ $2,522.64 = 1.11. The property covers its debt, but it misses the 1.25 that many DSCR lenders want for their best pricing.

The reverse math is what you need before you apply. At 1.25, the maximum PITIA is $2,800 ÷ 1.25 = $2,240. Take out $425 of taxes and insurance and $1,815 is left for principal and interest, which supports a loan of $259,577 at 7.5 percent. So you either bring about $40,000 more down payment, find a lower rate, or show rent of at least $3,153. The table under the results gives the max loan and required rent at 1.00, 1.10, 1.20, 1.25, and 1.50 in one view.

Switch to the NOI method with 5 percent vacancy and $400 a month of other costs and the same deal scores 0.87. A bank using that method would say no. This is why investors shop DSCR lenders instead of local banks for thin-margin rentals.

What DSCR do lenders require?

Common tiers in the residential DSCR market: 1.25 or higher gets the best rates and up to 80 percent loan-to-value on a purchase. Between 1.00 and 1.24 is usually still financeable, with a rate bump of roughly 0.25 to 0.75 points or a lower LTV. Under 1.00, some lenders offer no-ratio programs with 30 to 40 percent down and higher rates. Commercial and bank loans typically want 1.20 to 1.35 on the NOI method.

Lenders also look at credit score (often 660 to 700 minimum), cash reserves of 3 to 12 months of PITIA, and the appraisal's market rent (Form 1007) rather than your listing. If the property is vacant, the appraiser's rent estimate is the rent in the formula.

How to raise your DSCR

Bigger down payment: the fastest lever, because it cuts P&I directly. Buy down the rate with points; at these loan sizes one point often lowers the payment by $50 to $70 a month. Shop insurance, which is the second-largest line in PITIA in many states. Pick a 40-year term or an interest-only period if your lender offers them; both lower the payment, but you build equity more slowly. Raise rent to market before you refinance; a signed lease above the appraiser's estimate is often accepted.

Common mistakes

Using the wrong formula for your lender. Gross rent ÷ PITIA and NOI ÷ P&I can differ by 0.3 or more on the same property.

Forgetting HOA dues. They are the A in PITIA and can sink a condo deal.

Using your hoped-for rent instead of the appraised market rent. The lender uses the appraisal.

Treating 1.00 as safe. At 1.00 there is zero cushion; one vacant month or a $4,000 repair means paying the mortgage from your pocket.