Finance category
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Cash Flow per Door Calculator
Per-door cash flow is the standard quick-compare metric for small multifamily investors. Calculate cash flow per unit and across the whole portfolio from rent, vacancy, opex, and debt service.
Property
Loan (portfolio level)
Cash flow per door
-$44
monthly
Portfolio monthly cash flow
-$175
Annual portfolio cash flow
-$2,104
Debt service per door
$887
Reading the number
Negative per-door cash flow. This deal is only viable if you're betting on appreciation or significant rent growth.
Per-door cash flow is a quick portfolio comparison metric. Bigger properties typically have more headroom because operating expenses don't scale linearly. Small properties (1–4 units) need higher per-door cash flow targets to be safe.
EveryCalc calculators are designed for fast, practical estimates with transparent inputs and no required account. We use plain formulas, visible assumptions, and related tools so visitors can check the result from more than one angle.
Results are informational only. For financial, tax, legal, medical, construction, or other high-impact decisions, verify the output against primary sources or a qualified professional.
Learn more about our review process on the EveryCalc methodology page.
How this calculator works
What this page estimates
This Cash Flow per Door Calculator is built to give a quick, browser-based estimate for cash flow per door. Per-door cash flow is the standard quick-compare metric for small multifamily investors. Calculate cash flow per unit and across the whole portfolio from rent, vacancy, opex, and debt service. The inputs stay on the page during normal use, and the result should be treated as an estimate for planning, comparison, or education rather than professional advice.
Calculation approach
The calculator applies the standard relationship implied by the inputs, then formats the answer so it can be checked and reused. For finance tools, the most important step is using consistent units, rates, time periods, and assumptions before comparing the result with another calculator or outside quote.
Example workflow
For example, start with a realistic value you already know, change one input at a time, and watch how the answer moves. That makes it easier to tell whether the result is being driven by the main amount, the rate, the time period, or a unit conversion.
Practical checks
- Use current, real-world numbers when the result affects money, health, tax, or legal decisions.
- Run a low, base, and high case when the inputs are estimates.
- Check the related calculators below when the next decision depends on a different assumption.
How to interpret the cash flow per door result
Best use
Use the result as a planning number for comparing payments, rates, returns, tax reserves, or cash-flow choices before you request a quote or make a commitment.
Cross-check
Compare the answer with the contract, lender estimate, tax form, brokerage statement, payroll record, or invoice that will control the real-world outcome.
Watch for
Do not rely on a single optimistic rate, return, or fee assumption. Money pages work best when you run low, base, and high cases and keep professional advice separate from the estimate.
This page belongs to the Finance calculator library, so the answer should be read in the context of the decision you are modeling rather than as a universal rule.
Before relying on this cash flow per door estimate
Most calculator mistakes come from the inputs, not the arithmetic. Use this short audit before you reuse the answer in a spreadsheet, quote, application, or important conversation.
Confirm source numbers
Match balances, rates, fees, taxes, income, and payment dates against the lender quote, payroll record, tax form, statement, invoice, or contract.
Separate cash flow from total cost
A lower monthly payment can still cost more over time if fees, interest, taxes, or a longer term are hidden in the structure.
Run conservative cases
Test at least one higher-cost or lower-return case before using the output for a purchase, refinance, investment, loan, or tax decision.
Rerun this page when the rate, price, term, fee, tax rule, income, expense, or expected holding period changes.
How to Use
- Enter the number of units (doors) on the property.
- Enter average monthly rent per unit, vacancy, and per-unit operating expenses.
- Enter the loan amount, rate, and term at the portfolio level — the calculator divides debt service per door.
- Compare per-door cash flow to your minimum (commonly $100–$200/door for stabilized small multifamily).
Frequently Asked Questions
What's a healthy cash-flow-per-door number?
$100–$200/door is a common minimum for small multifamily after vacancy, opex, and debt service. Bigger properties (10+ units) often accept lower per-door because aggregated cash flow still works. Single-family rentals typically need $200+ per door for safety.
Why do investors compare per-door instead of total?
It normalizes properties of different sizes. A 4-plex generating $800/mo and a 12-plex generating $1,800/mo aren't equivalent — but per-door ($200 vs $150) shows the smaller property is more efficient.
Should capex be in operating expenses?
If you want a true cash flow figure, yes — set aside a capex reserve in opex per door. Otherwise a single roof or HVAC replacement can erase a year of cash flow on a small property.
Does this work for short-term rentals?
Yes for portfolio-style operators (multiple units), but the inputs change: variable nightly rent and higher opex (cleaning, supplies, OTA fees, dynamic pricing tools). For STRs, use ADR × occupancy in place of monthly rent × (1 − vacancy).
Related Calculators
Rental Cash Flow Calculator
Run full single-property cash flow with itemized expenses.
Cash on Cash Return Calculator
Convert per-door cash flow into a return on the cash invested.
Cap Rate Calculator
Compare cap rate next to per-door cash flow.
DSCR Calculator
Make sure the loan still passes the lender's DSCR floor.
Break-Even Occupancy Calculator
Find the occupancy floor below which per-door cash flow goes negative.
Rent Roll Calculator
Build the unit-by-unit rent roll that drives per-door averages.
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