Free rental analysis tool
Rental property cash flow calculator
Rent is the starting point. See what remains after vacancy, everyday expenses, financing and a reserve for major repairs. Change the assumptions to test the property you are considering.
Try the worked rental stress test. No signup required. Manual inputs only. See how the numbers are calculated.
Start with a hypothetical example
Every number is editable. These starting values are illustrative, not live rents, lender quotes or recommended assumptions. Nothing you enter is saved or sent by this calculator.
$162.53 / month estimated. View resultsYour estimated cash flow
Updates as you edit. Before income tax; no appreciation, sale proceeds or guaranteed returns.
Monthly net cash flow
After loan payment and capital reserve. A negative value is a modeled cash shortfall.
- Monthly loan payment
- $748.47
- Principal and interest only. Taxes and insurance are modeled separately.
- Annual net operating income (NOI)
- $11,832.00
- Rent after vacancy and operating expenses, before debt service, capital reserves and income tax.
- Cash invested upfront
- $45,000.00
- Down payment plus closing costs plus initial repairs. No additional opening cash reserve is included.
- Annual cash-on-cash return
- 4.33%
- Annual cash flow after the capital reserve divided by upfront cash invested. Principal paydown and appreciation are excluded.
Monthly calculation
- Scheduled rent
- $1,500.00
- Vacancy allowance
- -$75.00
- Rent after vacancy
- $1,425.00
- Tax, insurance, HOA & utilities
- -$250.00
- Management
- -$114.00
- Maintenance
- -$75.00
- Net operating income
- $986.00
- Loan payment
- -$748.47
- Capital reserve
- -$75.00
- Net cash flow
- $162.53
Worked rental example
Stress-test a rental before you make an offer
A rental can meet a rent-to-price rule of thumb and still leave little cash after expenses. The useful question is: what happens if one assumption is worse than expected?
Here is a calculation you can reproduce before spending more time on a candidate. All numbers are hypothetical, with no property address, market-rent claim or lender quote. The example is not a recommended budget or a buy/pass rule.
Start with the complete budget
Assume a $150,000 purchase, 25% down and a $112,500 fixed-rate loan at an illustrative 7% over 30 years. Monthly rent is $1,500. Tax is $150 a month, insurance $100, and HOA and owner-paid utilities are zero. Add $4,500 in closing costs and $3,000 in initial repairs.
Allow 5% for vacancy and collection loss, 8% for management, 5% for routine maintenance and 5% for capital reserves. These percentages are example inputs, not local estimates.
Rent is 1% of the purchase price. Rent minus the $748.47 principal-and-interest payment leaves $751.53, but that remainder has not paid the operating bills or funded future replacements. After those deductions, the modeled monthly cash flow is $162.53.
Change vacancy, keeping everything else fixed
Raise only the vacancy allowance from 5% to 20%. The table compares the original example with this stress scenario.
| Budget item | 5% vacancy | 20% vacancy |
|---|---|---|
| Scheduled rent | $1,500.00 | $1,500.00 |
| Vacancy allowance | −$75.00 | −$300.00 |
| Rent after vacancy | $1,425.00 | $1,200.00 |
| Tax and insurance | −$250.00 | −$250.00 |
| Management | −$114.00 | −$96.00 |
| Routine maintenance | −$75.00 | −$75.00 |
| Net operating income | $986.00 | $779.00 |
| Principal and interest | −$748.47 | −$748.47 |
| Capital reserve | −$75.00 | −$75.00 |
| Cash flow after reserve | $162.53 | −$44.47 |
The stressed example needs $44.47 a month from outside the rental under these assumptions. That is a $207 decline: $225 less rent, partly offset by $18 less management. A 20% allowance is a sensitivity exercise, not a forecast of vacancy or a literal schedule of empty months.
The calculation bases matter. Management is 8% of rent after vacancy: $1,425 × 8% = $114 in the original case. Maintenance and capital reserves each use scheduled rent: $1,500 × 5% = $75. Your management contract may use a different basis or charge additional fees.
Reproduce the result in the calculator above
- Choose Reset hypothetical example. This replaces any numbers you have entered, so copy your own assumptions first if you need them.
- Confirm the original result is $162.53 a month. Change only Vacancy allowance (%) from 5 to 20.
- Read the new Monthly net cash flow of −$44.47 and its monthly calculation. Then use evidence for your own property and change one assumption at a time.
Go to the vacancy input. The table is a fixed illustration; the calculator's result follows your inputs. It requires no account and does not look up rents, comps or property details.
Know what each number includes
This public calculator's net operating income (NOI) is rent after vacancy minus recurring operating expenses, before financing, capital reserves and income tax. The principal-and-interest payment excludes the tax and insurance already counted above. If your lender quotes an escrow-inclusive payment, separate its components to avoid counting those bills twice. The CFPB explains principal, interest, taxes and insurance.
The loan payment uses $112,500 × (0.07 ÷ 12) ÷ [1 − (1 + 0.07 ÷ 12)−360]. Keep full precision until displaying cents. This is a fully amortizing loan, not an interest-only or balloon loan.
The $75 capital reserve budgets for future major replacements. It does not say a repair occurs every month. For cash planning, distinguish money set aside from a bill paid out of that reserve. An average monthly allowance also does not show whether enough cash is available when a roof or turnover bill arrives.
Upfront modeled cash is $37,500 down + $4,500 closing costs + $3,000 initial repairs = $45,000. An additional opening cash reserve is not included. This public calculator includes initial repairs in its cash-on-cash denominator; check the included cash costs before comparing its percentage with another tool or saved deal.
Turn the stress test into an evidence checklist
- Support rent with relevant rental evidence or lease terms, including utility responsibilities.
- Check local vacancy, collection loss, leasing charges and turnover costs.
- Obtain property-specific tax and insurance estimates, including possible reassessment and additional coverage.
- Read the management agreement, including fee bases, minimums and extra charges.
- Inspect the property and obtain repair estimates; budget major replacements and opening cash separately.
- Confirm the actual loan terms, fees and closing costs. Account for expenses this simplified model omits, such as mortgage insurance and special assessments.
The point is to identify the assumption that deserves investigation before an offer. A positive estimate does not confirm future income, and a stressed shortfall does not create a universal rejection rule.
Put the review to work in Doormetrics
Use City Search in the signed-in workspace to review available inventory in your target market and shortlist candidates that fit your buying criteria. Review the saved deal's financing and rent assumptions, then inspect available closed-sale valuation evidence and its confidence level. Keep missing information visible and use it to frame the next agent questions.
Coverage, account access and remaining allowances affect available data and actions. Thin valuation evidence remains uncertain; a score does not replace an inspection or appraisal. If you are considering Section 8, use the rent-assumption guide to distinguish FMR, utility treatment and property-specific rent approval.
The public calculator's inputs are not saved or transferred into the account workspace. Doormetrics is a paid acquisition product with this free manual-input tool; nothing in this example is a live result from a listing. See the acquisition workflow.
How rental cash flow is calculated
Start with rent after vacancy. Scheduled monthly rent is reduced by your vacancy percentage. Management is charged on that remaining rent; maintenance and capital reserves are calculated from scheduled rent.
Separate the property from its financing. Net operating income (NOI) is rent after vacancy minus property tax, insurance, HOA, owner utilities, management and routine maintenance. This model excludes loan payments, capital reserves and income tax from NOI.
Estimate cash left each month. Net cash flow is NOI minus the loan payment and capital reserve. The loan assumes fixed interest and equal monthly principal-and-interest payments. A zero-interest loan divides the loan balance by the number of payments; 100% down means no loan payment.
Compare cash flow with cash invested. Annual cash-on-cash return is twelve months of estimated cash flow divided by the down payment, closing costs and initial repairs. It excludes appreciation, principal paydown and eventual sale proceeds. An additional opening cash reserve is not included in this denominator.
These are planning estimates before income tax, not a buy/pass recommendation. The model does not include every possible expense, such as leasing fees, special assessments or mortgage insurance. Budget for those separately and replace example values with your own evidence.
Using HUD Fair Market Rent as a starting point?
HUD Fair Market Rents (FMRs) are area-level gross-rent estimates. They include shelter rent and most tenant-paid utilities. A gross FMR figure is not automatically the rent paid to the owner. Check the relevant utility allowance and local housing agency requirements before entering a rent assumption here.
FMR is neither a guaranteed market rent nor approval of rent for a specific property. Housing Choice Voucher rents are subject to the local agency's rent-reasonableness process. This calculator does not retrieve FMR data or determine voucher eligibility.
Bring one market and one rental question
Bring your shortlist, assumptions and unanswered questions to a 15-minute Doormetrics demo. We can walk through the evidence behind the next agent conversation. Requesting a demo does not book a time or start a paid plan.