How to Calculate DSCR and Why Lenders Care

DSCR is the first test a lender runs and the one that most often decides how big a loan you can get. It's simple to compute and worth getting exactly right.

The formula

DSCR = NOI ÷ annual debt service. Debt service is the total principal and interest the loan requires over a year. A property with $250,000 NOI and $200,000 of annual debt service has a DSCR of 1.25x — NOI covers the loan payment with a 25% cushion.

How to calculate it, step by step

1. Compute NOI on real economics — effective gross income minus actual operating expenses and replacement reserves. Use the honest, post-reserves number; a pre-reserves NOI overstates coverage.
2. Compute annual debt service. During an interest-only period, that's interest only (a higher DSCR). Once the loan amortizes, use full principal + interest (a lower, more conservative DSCR). Lenders generally underwrite to the amortizing figure.
3. Divide. DSCR = NOI ÷ annual debt service.
4. Compare to the lender minimum — typically 1.20x–1.25x, sometimes 1.30x+ for conservative lenders or weaker assets.

The free DSCR calculator does steps 3–4 instantly and tells you whether you clear a 1.20–1.25x threshold.

Why lenders care — and why it caps your loan

DSCR is the lender's margin of safety: how far NOI can fall before the property can't pay its mortgage. That's why it usually sizes the loan before LTV does.

Work it backwards. If NOI is $250,000 and the lender requires 1.25x, the maximum annual debt service is $250,000 ÷ 1.25 = $200,000. The loan amount is whatever balance produces a $200,000 annual payment at the quoted rate and amortization. If that DSCR-constrained loan is smaller than the LTV-constrained loan, DSCR is your binding constraint — you'll need more equity than the LTV alone implied.

Reading the result:

• ≥ 1.25x — clears a typical minimum with cushion.
• 1.0x–1.20x — covers debt but thin; many lenders won't fund it.
• < 1.0x — operations don't cover the loan; the deal needs a lower price, more equity, or higher NOI.

A worked example

A deal with $250,000 NOI and a loan requiring $230,000 of annual P&I has a DSCR of 1.09x — below a 1.25x minimum. To clear it, the lender caps debt service at $200,000, which means a smaller loan and roughly $300,000+ more equity at close, or a price reduction. Catching that on the DSCR calculator before you write the offer is the difference between a financeable deal and a surprise at term sheet.

Worked example — DSCR at a 1.25x lender floor

The discipline: most lenders set a 1.20x–1.25x DSCR floor; at 1.25x this deal just clears with no cushion.

UpsideIQ flags DSCR against your own minimum on every deal — at both the interest-only and amortizing scenarios — so you see the financing constraint before the lender does. Try the free DSCR calculator.