How to evaluate a property’s cash flow potential

Q: What is a good cash-on-cash return on a rental property?

Many buy-and-hold investors target 8% to 12% cash-on-cash, though acceptable returns vary sharply by market. In high-appreciation metros investors often accept 4% to 6% because the return comes from value growth. In flatter Midwestern markets, cash flow does the work and investors expect double digits. Compare against your alternative uses of the same capital.

Written by Samantha SheltonNMLS 1647301Updated September 2026

Investor working through rental numbers at a dining table while evaluating a property's cash flow potential

This article is general education about building a rental pro forma. It is not tax advice, not investment advice, and not an offer to buy or sell any security. Depreciation, deductions and entity choice depend on your facts, take those to a CPA or qualified tax professional. Align Lending is an independent Michigan mortgage broker; it is not a broker-dealer, investment adviser, or property manager.

Evaluating a specific property’s cash flow potential is one chain of subtraction applied to numbers you have to go out and source: gross scheduled rent minus vacancy plus other income equals effective gross income, minus operating expenses equals net operating income, minus annual debt service equals your before-tax cash flow. The line that most often makes that chain lie is vacancy, the U.S. rental vacancy rate was 7.3% in the second quarter of 2026, according to the Census Bureau’s Current Population Survey/Housing Vacancy Survey, so a worksheet built on twelve collected months is overstating income before you have priced a single expense.

This is the applied worksheet, not the concept. For the definitions, what cash flow is and why it differs from profit, start with our guide to cash flow in real estate. Here you’ll learn how to build the pro forma line by line, where to source each input, how to size the vacancy and reserve lines, how to stress-test the assumptions, and which mistakes make a pro forma lie.

Key takeaways:

Build every line, don’t shortcut to the payment: On the duplex modeled below, a three-line worksheet of rent, taxes and insurance shows $16,527 of annual cash flow while the full build shows $3,852, the shortcut overstates the deal by 4.3 times.
Underwriters already discount rent by 25%: Fannie Mae’s Selling Guide has lenders multiply gross monthly rent from Form 1007 or Form 1025 by 75%, with the other 25% absorbed by vacancy and ongoing maintenance. Your worksheet should be at least that conservative.
Stress-test before you sign, not after: Four ordinary misses (vacancy at 12% instead of 8%, rents 5% light, a rate half a point higher, and a 25% tax reassessment) turn that same $3,852 of cash flow into negative $305.

What belongs on a rental pro forma, line by line?

Eleven lines, in a fixed order, each carrying a dollar figure before you make an offer. Order matters because every line feeds the next: skip vacancy and everything under it is wrong by the same percentage. Build it with one column for the number and one for where the number came from. The second column is what you defend when the property underperforms.

Line	How it’s calculated	Where the number comes from
Gross scheduled rent	Market rent per unit × units × 12	Signed leases, comparable listings, HUD Fair Market Rents
Vacancy and credit loss	Gross scheduled rent × vacancy rate	Submarket vacancy data, not the seller’s occupancy claim
Other income	Laundry, storage, parking, pet rent	Seller’s operating statement, verified against deposits
Effective gross income	Scheduled rent − vacancy + other income	Calculated
Fixed operating expenses	Taxes, insurance, owner-paid utilities, licensing	Assessor record, insurance quote, utility billing history
Variable operating expenses	Repairs, turnover, lawn and snow, management	Contractor bids, management quotes, trailing 12-month invoices
Capital expenditure reserve	Replacement cost ÷ remaining useful life	Inspection report ages plus local replacement bids
Net operating income	Effective gross income − operating expenses	Calculated
Annual debt service	Monthly principal and interest × 12	A quoted loan scenario, not a rate you saw online
Before-tax cash flow	Net operating income − debt service	Calculated
Cash-on-cash return	Before-tax cash flow ÷ total cash invested	Calculated

Two lines carry more weight than the rest. Net operating income is calculated before financing, which is why it travels between properties. Cash-on-cash return answers whether this deal deserves your capital. Keep them on separate rows; collapsing them is the most common structural error in a beginner’s worksheet.

Where does each number actually come from?

From primary records you pull yourself, in priority order: signed documents first, government data second, listing-site estimates last. Every input should trace to a source you could show a partner. The market work that comes before any single property sits in analyzing rental market trends and how to analyze a property’s rental potential.

Rent: Start with the signed leases and an estoppel certificate from each tenant, because stated rent and collected rent are different numbers. For a vacant or under-rented unit, HUD publishes Fair Market Rents, estimates of 40th-percentile gross rents for standard-quality units by metro area and nonmetro county, built for fiscal year 2026 on 2019–2023 American Community Survey data. Treat it as a floor reference, not a market rate. Commercial rent indexes published by listing portals are useful cross-checks, but they model asking rents, not collected rents.
Vacancy: Use a submarket figure, then check it against the 7.3% national rate for the second quarter of 2026 from the Census Bureau’s Housing Vacancy Survey. If your submarket number sits far below the national rate, ask who produced it.
Property taxes: Pull the parcel from the county assessor, then confirm what happens at transfer, in many jurisdictions taxable value resets when the property sells, so the seller’s tax bill is not your tax bill. See how property tax assessments work.
Insurance and utilities: Get a written landlord-policy quote for this address rather than a rule of thumb, since roof age, claims history and loss-of-rents coverage all move the premium. Then ask for 24 months of billing history on anything the owner pays; water and sewer on small multifamily is frequently owner-paid and frequently forgotten.
Repairs and capital items: Take the ages of the roof, furnace, water heater, service panel and windows off the inspection report, then price replacement with a local contractor. This is the heart of real estate due diligence.
Historical operations: Request the trailing 12 months of income and expenses, and the seller’s Schedule E on a larger deal. Read them as a starting point, not a verdict. An owner who self-managed and deferred maintenance shows expenses you cannot replicate.

How much should you reserve for vacancy, maintenance and capital expenditures?

Enough that the reserve lines stay real expenses in the months you don’t spend them. Standard practice puts vacancy at 5% to 10% of gross scheduled rent, repairs at roughly 5% to 10%, and capital reserves at another 5% to 10%, rules of thumb, not laws, and the last two belong on separate lines because they behave differently. Repairs are the leaking faucet. Capital expenditures are the roof.

Underwriting already applies its own version of this haircut. Under Fannie Mae’s Selling Guide, when a lender uses current leases or market rents reported on Form 1007 or Form 1025, it multiplies gross monthly rent by 75%, with the remaining 25% absorbed by vacancy losses and ongoing maintenance. If your worksheet is more optimistic than the lender underwriting the loan, that says something about your worksheet.

Build the capital reserve from components, not from a percentage: replacement cost divided by remaining useful life, summed. On the two-unit building modeled below, a $12,000 roof over 25 years is $480 a year, two furnaces at $10,000 over 18 years is $556, two water heaters at $3,200 over 11 years is $291, flooring at $12,000 over 12 years is $1,000, and two appliance sets at $4,000 over 12 years is $333.¹ That totals $2,660 a year, or $222 a month, owed whether or not anything breaks.

Management, even if you self-manage: Budget the market rate, commonly quoted at 8% to 10% of collected rent in Midwestern markets, because the deal has to still work the day you hand the building to a manager. See how to manage a rental property.
Turnover, separate from repairs: Cleaning, paint, locks, listing and lost rent between tenants. One turn a year on a duplex is a normal assumption, not a pessimistic one.
Deferred maintenance you inherit: Anything the inspection flags for year one is a closing-cost item, not a reserve item. Put it in total cash invested.

What does the worked example look like on one duplex?

Carried end to end, a $220,000 duplex renting for $1,450 a unit produces $3,852 of before-tax cash flow and a 5.9% cash-on-cash return about $321 a month, or $160 per unit. Every figure below is hypothetical and shown to demonstrate the method.² Financing assumed: 25% down ($55,000), a $165,000 30-year fixed loan at an illustrative 7.00%, $5,500 in closing costs and $4,500 of make-ready work, for $65,000 of cash invested.

Line	Annual amount
Gross scheduled rent (2 × $1,450 × 12)	$34,800
Less vacancy and credit loss at 8%	−$2,784
Plus other income (coin laundry)	+$600
Effective gross income	$32,616
Property taxes	$3,300
Landlord insurance	$1,800
Water and sewer (owner-paid)	$1,200
Lawn care and snow removal	$900
Repairs and maintenance	$1,800
Capital expenditure reserve	$2,660
Property management at 9% of collected rent	$2,881
Turnover and leasing	$700
Licensing, accounting and legal	$350
Total operating expenses	$15,591
Net operating income	$17,025
Less annual debt service	−$13,173
Before-tax cash flow	$3,852
Total cash invested	$65,000
Cash-on-cash return	5.9%

Three readings come out of that table. Operating expenses run 47.8% of effective gross income, inside the range experienced operators expect on small multifamily. Net operating income covers debt service 1.29 times, a coverage ratio lenders in Align’s network watch closely on investment files.³ And 5.9% is below the 8% to 12% many buy-and-hold investors target, a rule of thumb rather than a published benchmark, and information rather than a verdict. It tells you to negotiate price, push rents, or move on.

Now run the same property through the shortcut most first-time buyers use. Rent of $34,800, minus $3,300 in taxes, minus $1,800 in insurance, minus $13,173 of debt service, equals $16,527, or about $1,377 a month. That is not slightly optimistic. It is 4.3 times the honest answer, and every dollar of the gap is a bill that arrives anyway. See how to become a real estate investor and our investing basics hub.

How do you stress-test the assumptions before you write the offer?

Change one input at a time, then all four at once, and see whether the deal survives. A single-scenario pro forma is a guess wearing a spreadsheet. These four variables are the ones that actually move in the first two years of ownership.

Scenario	Before-tax cash flow	Cash-on-cash return
Base case	$3,852	5.9%
Vacancy at 12% instead of 8%	$2,585	4.0%
Rents come in 5% under projection	$2,395	3.7%
Interest rate 0.50 points higher	$3,180	4.9%
Property taxes reassessed 25% higher	$3,027	4.7%
All four together	−$305	−0.5%

None of those four is a disaster scenario. Each is an ordinary miss, and together they erase the deal. Two more tests belong on the same sheet.

Break-even occupancy: Solve for the collection level where cash flow reaches zero. On this duplex it lands near 80%, so the property can lose about a fifth of scheduled rent before it stops paying for itself. A deal that breaks even at 95% has no margin at all.
The capital shock test: Assume one major system fails in year one. A $5,000 furnace against a $2,660 reserve leaves $2,340 out of pocket and cuts cash flow by more than half. If one furnace wipes out the year, the deal is thinner than the return suggests.

Debt amplifies in both directions, which is the honest version of the leverage argument, see real estate leverage. And none of this forecasts appreciation. Past performance never predicts future results, and a property that only works if values rise is a bet on the market, not a cash-flowing asset. Our guide to cap rates in real estate covers the other lens on the same income.

Which mistakes make a pro forma lie?

Seven, and six are omissions rather than errors. Each one makes the sheet look better than the building.

Assuming twelve collected months: With national rental vacancy at 7.3% in the second quarter of 2026, a 100%-occupancy assumption is not aggressive underwriting, it is no underwriting.
Merging repairs and capital expenditures: A $150-a-month repair allowance does not fund a roof. Reserve them separately or the roof arrives as a surprise.
Zeroing out management because you’ll self-manage: Unpaid labor is still a cost, and it disappears the moment you get busy, move away, or scale.
Inheriting the seller’s expense numbers: Insurance reprices to your policy and taxable value often resets on transfer. The seller’s operating statement describes the seller’s ownership.
Counting principal paydown as cash flow: Amortization builds equity, but it is not money in your account this month, and mortgage principal is not a deductible expense. Only the interest is, per IRS guidance on deductible rental operating expenses.
Putting depreciation on the cash flow line: Depreciation changes taxable income, not your bank balance, so it belongs below the cash flow line, and the recovery period, the land-and-building basis split and the recapture that follows are set out in real estate depreciation. Confirm treatment with a CPA.⁴
Skipping the financing quote: Debt service was 40% of effective gross income above. A worksheet built on an assumed rate has its largest single expense set by a guess.

That last one is where a broker changes the number. Down payment, term, amortization and product type all move debt service, and the same borrower and building can produce materially different cash flow depending on which wholesale lender prices the file, start with how to finance a real estate investment and buying a home as an investment property. Plan for the reserve requirement too: under Fannie Mae’s Selling Guide, Desktop Underwriter requires six months of reserves on an investment property transaction, and a borrower who owns other financed properties owes additional reserves calculated on the aggregate unpaid principal balance of those other properties, 2% at one to four financed properties, 4% at five to six, and 6% at seven to ten. That is cash that must exist after closing. Broader strategy sits in our real estate investing guide.

How Align finances investors

A rental has to work as an investment, not just as a house you happen to like. Samantha looks at the property's numbers before the loan's.

Align places DSCR loans, which qualify on the rent the property brings in rather than your tax returns, as well as conventional investment loans, through multiple wholesale lenders.

Review an investment property

FAQ: Evaluating a property’s cash flow potential

Here are answers to common questions about evaluating a property’s cash flow potential.

What is a good cash-on-cash return on a rental property?

There is no published standard. Many buy-and-hold investors target 8% to 12% as a rule of thumb, though acceptable returns vary sharply by market. In high-appreciation metros investors often accept 4% to 6% because the return is expected to come from value growth. In flatter Midwestern markets, cash flow does the work and investors expect double digits. Compare the number against your alternative uses of the same capital, and against the property’s underlying deal quality.

What expenses do investors most often forget?

Capital expenditure reserves for roof, furnace, water heater and flooring; turnover costs including cleaning, paint and lost rent between tenants; property management at 8% to 10% of collected rent even if you self-manage today; snow removal and lawn care; and the premium increase that comes with converting to a landlord policy. Building the reserve from component life rather than a flat percentage is the fix, the same discipline used in budgeting for home maintenance.

How is cash flow different from net operating income?

Net operating income measures the property’s performance before financing, which is why it is used for valuation and cap rate. Cash flow measures what lands in your account after the mortgage payment. Two identical buildings have the same net operating income but very different cash flow if one carries a 20-year loan and the other a 30-year loan, which is why amortization schedules belong next to your pro forma.

How do I improve a property’s cash flow?

Raise income or cut expenses. Income levers include bringing under-market rents to market at renewal, adding billable amenities like in-unit laundry or reserved parking, and reducing vacancy through better tenant retention. Expense levers include appealing an inflated property tax assessment, rebidding insurance annually, and refinancing when your equity position or the rate environment improves, see how to refinance an investment property.

The bottom line on evaluating cash flow potential

A property’s cash flow potential is only as honest as its weakest input. Build all eleven lines, source each from a signed document or a government dataset, set vacancy at a rate you can defend against the 7.3% national figure for the second quarter of 2026, and reserve for capital expenditures by component life rather than by guess. On the duplex above, the disciplined build returned $3,852 a year and 5.9% cash-on-cash while the three-line shortcut claimed $16,527, and four ordinary misses took that same deal to negative $305.

If you’re ready to price the debt service line with real numbers, talk to Align Lending. We’ll shop your investment scenario across our lender network and show you how each structure changes the cash flow, side by side. Call 248-506-5727 or start online today. Take depreciation, basis and entity questions to a CPA, and legal questions to a Michigan attorney.

Footnotes:

1. Example figures are hypothetical and for educational purposes only. The replacement costs and useful lives shown for roof, furnaces, water heaters, flooring and appliances are illustrative Align Lending calculations used to demonstrate the component-reserve method, not estimates for any particular property or market. Obtain local contractor bids and a professional inspection for your own numbers. Return to text.

2. Example figures are hypothetical and for educational purposes only; they do not constitute an advertisement of credit terms or a rate quote under federal or state lending laws. The $220,000 purchase price, $1,450 per-unit rent, 8% vacancy assumption, individual expense lines, $55,000 down payment, $165,000 loan amount, 30-year term, 7.00% illustrative interest rate, $5,500 in closing costs and $4,500 of make-ready work are Align Lending calculations shown to demonstrate how a rental pro forma is built. They are not a projection of results for any property and do not reflect income taxes, depreciation, or any current market rate. Your rate and terms will depend on your application, program guidelines, and market conditions. Return to text.

3. Debt-service coverage expectations, reserve requirements, down payment minimums and loan-level pricing adjustments on investment property are set by individual lenders and by agency guidelines, vary by program and borrower profile, and are subject to change. Align Lending does not set these terms; lenders in our network do. This is not a commitment to lend. Return to text.

4. This is general information, not tax advice. Depreciation method and recovery period, allocation of basis between land and improvements, the distinction between deductible repairs and capitalized improvements, passive activity loss limits, and the treatment of depreciation on a later sale all depend on your individual circumstances and on current law. Consult a qualified tax professional or CPA about your situation. Return to text.

Sources: National rental vacancy rate of 7.3% and homeowner vacancy rate of 1.2% in the second quarter of 2026, median asking rent of $1,531 for vacant for-rent units, U.S. Census Bureau, Current Population Survey/Housing Vacancy Survey, released July 28, 2026. Requirement that lenders multiply gross monthly rent from Form 1007, Single-Family Comparable Rent Schedule, or Form 1025, Small Residential Income Property Appraisal Report, by 75%, with the remaining 25% absorbed by vacancy losses and ongoing maintenance expenses, Fannie Mae Selling Guide B3-3.8-01, Rental Income. Desktop Underwriter requirement of six months of reserves on an investment property transaction, and additional reserves for borrowers with multiple financed properties equal to 2% of the aggregate unpaid principal balance for one to four financed properties, 4% for five to six, and 6% for seven to ten, Fannie Mae Selling Guide B3-4.1-01, Minimum Reserve Requirements. Fair Market Rents defined as estimates of 40th-percentile gross rents for standard-quality units within a metropolitan area or nonmetropolitan county, including shelter rent plus tenant-paid utilities other than telephone, cable or satellite television and internet, 24 CFR 888.113; fiscal year 2026 Fair Market Rents based on 2019–2023 five-year American Community Survey estimates of two-bedroom adjusted standard-quality gross rents, U.S. Department of Housing and Urban Development, Office of Policy Development and Research. Deductible rental operating expenses, non-deductibility of mortgage principal payments, and the distinction between deductible repairs and capitalized improvements, Internal Revenue Service Publication 527, Residential Rental Property. Vacancy, maintenance, capital reserve and property management percentage ranges, and the 8% to 12% cash-on-cash return target, are widely used industry rules of thumb, not published statistics or benchmarks, and are labeled as such in the text. They carry no predictive force, and past performance does not predict future results.

This article is for informational purposes only and is not intended to provide legal, financial, investment, or tax advice, and is not a recommendation to buy or sell any property or security. Market data, agency guidelines, loan program requirements and tax rules change and vary by program, property, and locality; confirm current figures with your loan officer, confirm tax treatment with a qualified tax professional or CPA, and confirm legal questions with a Michigan attorney. Figures shown are illustrative, are not a rate quote or an offer of credit, and do not constitute an advertisement of credit terms. Past performance does not predict future results. Align Lending is an independent Michigan mortgage broker, NMLS #2041154, and is not a broker-dealer, investment adviser, securities issuer, or property manager.