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DSCR loan math

How to Calculate DSCR Loan Amount

The coverage test runs forward: eligible rent ÷ PITIA. Max loan runs the same formula backward. This page shows the inversion, a worked example, and the calculator in Max loan mode — not a third calculator URL. Compare typical metro rent gaps on the DSCR Investor Index, then invert a specific rent here.

  • Max PITIA = eligible rent ÷ target DSCR
  • Then subtract taxes, insurance, and HOA
  • Solve the leftover payment for principal
  • Cap the result by LTV when a price is known

The two formulas

Residential DSCR loans used for 1–4 unit rentals commonly compare eligible monthly rent with PITIA (principal, interest, taxes, insurance, association dues). That is different from commercial bank DSCR, which often uses annual NOI ÷ annual debt service. This page stays on the residential inversion.

1. Coverage (forward)

DSCR = eligible monthly rent ÷ PITIA

Use this when you already have a price, down payment, and estimated payment. It is the default mode on the DSCR loans hub calculator.

2. Max loan (backward)

Max PITIA = eligible monthly rent ÷ target DSCR

Max P&I = max PITIA − taxes − insurance − HOA. Convert that payment to principal, then take the lower of the DSCR-supported loan and value × max LTV.

Worked example

Same starter scenario used on the hub: $3,200 gross rent, 5% vacancy, $350 taxes, $150 insurance, 7.25% illustrative 30-year rate, $425,000 price, 80% max LTV.

  1. Eligible rent. $3,200 × (1 − 5%) = $3,040.00.
  2. Max PITIA at 1.00 DSCR. $3,040.00 ÷ 1.00 = $3,040.00.
  3. Max P&I. $3,040.00$350 $150 = $2,540.00.
  4. DSCR-only principal. That payment at 7.25% / 30 years supports about $372,338.
  5. LTV cap. 80% of $425,000 is $340,000. The binding max loan is $340,000 (LTV binds).
Target DSCRMax PITIADSCR-only loanAfter 80% LTV cap
1.00$3,040.00$372,338$340,000
1.25$2,432.00$283,211$283,211

A 1.25 target shrinks payment room, so the DSCR-only loan falls from $372,338 to $283,211. That is the tradeoff investors model before they offer.

Max loan calculator

Same engine as the hub. Switch to Analyze coverage if you already have a loan amount. Interest-only is on this mode so you can see how a lower payment changes the inverted principal.

Max DSCR Loan Amount

Invert eligible rent and a target DSCR to estimate max loan. Interest-only is available on this mode.

$425,000
$0$5,000,000
$3,200
$0$50,000
7.250%
0.000%15.000%
$350
$0$5,000
$150
$0$3,000

Target DSCR

80%
50%90%

Caps the DSCR-supported loan against property price

Simple mode uses a 5% vacancy allowance and a $150 maintenance estimate. Adjust both in Advanced.

Illustrative max loan

$283,211

Supported by 1.25 lender-style DSCR before any LTV cap.

Educational estimate — not an approval or rate quote.

Eligible monthly rent

$3,040.00

Max PITIA at target

$2,432.00

Max principal & interest

$1,932.00

DSCR-only max loan

$283,211

LTV-capped max loan

$340,000

Cash needed if price is used

$141,789

Max loan by target DSCR

1.00

$340,000

1.10

$331,826

1.15

$314,212

1.20

$298,066

1.25

$283,211

Interest-only vs amortizing

Same rent and target DSCR. Interest-only lowers the monthly debt service, so the inverted principal is higher — pricing and qualification still differ.

Amortizing max (DSCR only)

$283,211

Interest-only max (DSCR only)

$319,779

Full walkthrough: How to calculate DSCR loan amount.

Interest-only vs amortizing

Interest-only PITIA uses rate × balance instead of a fully amortizing P&I. On the starter scenario, a 1.00 target supports about $420,414 interest-only versus $372,338 amortizing — before the LTV cap. That larger IO principal is why some investors model IO to make a thin rent file look workable. It is still not an approval, and IO pricing differs.

See DSCR loan rates for what typically moves pricing, including structure.

What the max-loan number does not decide

Inverting DSCR answers “how much payment can this rent support?” Lenders still review credit, reserves, occupancy, property type, lease or rent-schedule documentation, and whether the file is purchase, rate/term, or cash-out. Typical market ranges — including $100K–$3M+ loan size and 20–25% down — live on the DSCR loan requirements guide.

Gross rent is not automatically qualifying income. Many purchase files use the lesser of lease rent and the appraisal rent schedule. Short-term rental income often has a stricter path.

DSCR loan amount questions

Eligible monthly rent after vacancy, divided by the target DSCR, is the maximum PITIA. Subtract taxes, insurance, and HOA. Solve the remaining payment for an illustrative principal at the stated rate and term. An LTV cap can still bind below that DSCR ceiling.