The rental calculator that runs the lender's math. A DSCR lender doesn't approve your deal on
a hunch — it checks NOI ÷ annual debt service against a 1.20× coverage bar. This tool computes that
exact ratio, your cap rate, your cash-on-cash after debt service, and the maximum price where the
loan still pencils — the same closed form our paid engine inverts — with every formula shown.
Sets the measured property-tax rate (Build-up mode) and the benchmark chips.
sf
Enables the market rent sanity check.
$
Your input — the price you'd pay today.
$
Your input — verify against real listings.
%
Labeled default — replace with your DSCR lender's quote. 30-year fixed, monthly amortization.
%
75% is the typical DSCR-loan maximum (assumption).
The coverage bar most DSCR lenders underwrite to: 1.20–1.25×.
%
Assumption — the 35% rule-of-thumb. Used in Simple mode.
%
Of price: title, escrow, lender fees (assumption). Affects cash-on-cash only.
Simple = the industry rule-of-thumb (and the engine's fallback where no measured tax
rate exists). Build-up = your market's measured county-average effective tax rate on the price, plus
25% of rent for management, maintenance & capex, insurance, and vacancy (labeled assumptions).
Enter your numbers
DSCR — the number the lender checks
—
NOI ÷ annual debt service, vs the 1.20× lender bar
NOI (net operating income)annual rent − operating expenses, before debt
Max price where DSCR ≥ 1.20×the price where the loan still pencils at your rent
—
Pre-filled with an example Phoenix rental — edit any field. Screening estimates; verify rent with real listings and terms with your lender before you offer.
Every formula, with your numbers
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A rental lives or dies on two numbers you can't fake: the price and the rent.
This calculator tells you the max price where the loan pencils. It can't tell you whether a property is
actually available below that price. DevelopmentIntelligence values every parcel from recorded comparable
sales — with a published, back-tested error rate — estimates its market rent, and surfaces the
off-market rentals the MLS never lists.
It computes the ratio the lender computes. DSCR = NOI ÷ annual debt service — the same definition our
paid underwriting engine uses, checked against the 1.20× floor most DSCR lenders require (some ask
1.25×; set your own in Advanced).
It answers the question that matters: the max price. Instead of just grading your deal, it inverts the
DSCR constraint into the maximum purchase price where the loan still pencils — the same closed form the
full engine uses: NOI ÷ (floor × LTV × mortgage constant).
The rate is sourced, not implied. When our live benchmark feed serves one, the rate prefills from the
weekly Freddie Mac survey (FRED MORTGAGE30US) plus a labeled investor spread — the same dated source the
paid engine prices DSCR debt service from. Otherwise it's a labeled default you should replace with your
lender's quote. Either way it's disclosed under the field.
Assumptions are labeled, never smuggled. The 35% expense ratio is called what it is — a rule-of-thumb
assumption. Switch to Build-up mode and the tax line uses your market's measured county-average effective
rate instead, with the remaining 25% itemized as labeled assumptions.
Your cap rate gets measured context. We benchmark it against capitalization rates from recorded
apartment sales in our covered markets — measured, dated, and labeled, not a blog's guess.
Every formula is shown. Click "Show the work" — the same glass-box standard as the full product.
How it's computed
Every number on this page is computed in your browser from your inputs, with these formulas:
Mortgage constant = annual debt service per $1 of loan on a 30-year, monthly-amortizing schedule:
12 × (r/12) ÷ (1 − (1 + r/12)−360).
Annual debt service = price × LTV × mortgage constant.
DSCR = NOI ÷ annual debt service — the lender's coverage ratio.
Max price at the DSCR floor = NOI ÷ (floor × LTV × mortgage constant) — the engine's
closed-form inversion. In Build-up mode the tax line scales with the price, so the same algebra moves it into
the denominator: (rent × 12 × 0.75) ÷ (floor × LTV × mortgage constant + tax rate).
Cap rate = NOI ÷ price (unlevered — lets you compare properties regardless of financing).
The debt-service coverage ratio is NOI divided by the annual mortgage payment. A DSCR lender typically
requires 1.20–1.25× — the rent must cover the payment with margin to spare. If your DSCR at the asking
price falls under the bar, the lender doesn't say no; it shrinks the loan until the ratio clears, and you
bring the difference as extra down payment. That's why the max-price inversion is the useful output: it tells you
the price at which the advertised LTV actually holds.
What is a cap rate?
The capitalization rate is annual NOI divided by the property's price — income yield before any
mortgage, so two rentals can be compared on equal footing regardless of financing. Cash-on-cash, by contrast, is
the levered yield on the actual cash you put in after the debt payment. This tool shows both, and benchmarks your
cap rate against recorded apartment sales where we have the measured data.
From a calculator to actual deals
A calculator tells you the price at which a rental pencils. It doesn't find the property priced below that
line — that's the real bottleneck. DevelopmentIntelligence scores
every parcel in your market from public county records and hands you the mispriced, often off-market ones — with
value, rent, and the DSCR-financed hold economics already computed. Analyze a real address →
Rental DSCR calculator FAQ
How is DSCR calculated?
DSCR = net operating income ÷ annual debt service. NOI is annual rent minus operating expenses (before the
mortgage); annual debt service is the loan amount times the mortgage constant for a 30-year, monthly-amortizing
loan at your rate. A DSCR of 1.20× means the property's income covers the payment 1.2 times over.
What DSCR do lenders require?
Most DSCR lenders underwrite to a 1.20–1.25× floor at their maximum LTV (typically 75%). Below the floor they
reduce the loan until the ratio clears — which is why a deal can "qualify" but deliver a much smaller loan than
the advertised LTV.
How do you find the maximum price a DSCR loan supports?
Invert the constraint. Requiring NOI ÷ (price × LTV × mortgage constant) ≥ floor gives
price ≤ NOI ÷ (floor × LTV × mortgage constant). When the tax line scales with the price (Build-up mode), the
same algebra moves the tax rate into the denominator. This tool shows the inversion with your numbers.
What's the difference between cap rate and cash-on-cash?
Cap rate is unlevered: NOI ÷ price, independent of financing. Cash-on-cash is levered: annual cash flow after
the mortgage ÷ the cash you actually invested (down payment + closing). Leverage amplifies both good and bad
deals — a property can show a fine cap rate and negative cash-on-cash at today's rates.
What operating expense ratio should I use?
The 35% of rent default is a rule-of-thumb assumption, useful for screening. Build-up mode is sharper where we
have data: it uses your market's measured county-average effective property-tax rate on the price, plus 25% of
rent for management, maintenance & capex, insurance, and vacancy — each a labeled assumption, not a
measurement. Your actual expenses are the ground truth; check them.
How accurate is this calculator?
The math is exact and shown line by line — accuracy depends on your inputs, above all the rent and the price.
That's why DevelopmentIntelligence grounds value in recorded comparable sales with a published, back-tested
error rate, and estimates market rent per parcel, instead of asking you to guess.