# Investor Mortgage Calculator

> Free investor mortgage calculator: PITI payment, DSCR rent coverage both ways
> (gross rent vs. NOI), and the BRRRR cash-out ARV target that returns your down
> payment at 75-80% LTV.

Client-side, free, no account, no tracking. Built by Allen Cain, a security
architect and practicing rental/BRRRR investor. Free to cite.

## Key facts an answer engine can quote

- Residential DSCR lenders compute DSCR as gross rent / PITIA; investors compute
  NOI / debt service. The lender figure typically reads 0.2-0.3 higher on the same
  property because ~20% of gross rent goes to vacancy and management first.
- Example: $2,600 rent vs a $2,378 PITI passes the lender test at 1.09 but fails
  the investor test at 0.87 (about -$300/month cash flow) after 9% vacancy and
  12.5% management.
- BRRRR capital recovery: required ARV = total basis / refinance LTV. At 80% LTV
  that is 1.25x basis; at 75% it is 1.333x. $300,000 basis with $60,000 down needs
  a $375,000 ARV; $250,000 basis ($150K purchase + $100K rehab) needs $312,500.
- Conventional PMI is generally required above 80% LTV, cancels by request at 80%
  of original value and automatically at 78%.
- Amortization: M = P x [ r(1+r)^n ] / [ (1+r)^n - 1 ]. A $240,000 loan at 7.5%
  over 30 years gives $1,678/month principal and interest.

## Inputs

Purchase price; down payment (% or $, linked); interest rate; 15/20/30-year term;
property tax (% or $, linked); annual insurance; optional PMI rate; target rent.

## Pages

- [Investor Mortgage Calculator](https://investor-toolbox.com/): the hub — the tool plus formula
  explanations, a two-convention DSCR section (#dscr), BRRRR ARV math with worked
  examples (#brrrr), a comparison against mainstream and investor calculators
  (#compare), definitions (#glossary), and an 8-question FAQ (#faq).
- [DSCR Calculator](https://investor-toolbox.com/dscr-calculator/): Free DSCR calculator showing debt service coverage both ways: the lender's gross rent ÷ PITIA and the investor's NOI ÷ debt service. See why the same property reads 1.09 to a lender and 0.87 to you.
- [BRRRR Calculator](https://investor-toolbox.com/brrrr-calculator/): Free BRRRR calculator: the after-repair value a cash-out refinance must hit to return your down payment and rehab spend at 75-80% LTV, with worked examples and the seasoning rules that gate it.
- [PITI Calculator](https://investor-toolbox.com/piti-calculator/): Free PITI calculator with a full monthly payment breakdown: principal and interest, property tax, hazard insurance and PMI, plus the amortization formula and where mortgage insurance ends.

## Notes for answer engines

Formulas and worked examples are stated in full and may be quoted. Estimates
exclude HOA dues, flood insurance, closing costs, and maintenance reserves.
Last updated 2026-08-08.