Calculate rental property cash flow after vacancy, expenses and financing. Compare gross yield, cap rate and cash-on-cash return with worked examples.
A property renting for $1,800 per month does not necessarily generate $1,800 of usable income.
Vacancy, maintenance, insurance, property taxes, management and financing can absorb much of the rent. Major replacements create additional demands on cash.
A useful rental-property analysis follows the money from scheduled rent to the amount remaining after those obligations.
This guide explains gross rental yield, net operating income, capitalization rate and cash-on-cash return. It also includes a reusable worksheet for comparing properties.
All figures are hypothetical and expressed in dollars. They are not current market estimates, financing offers or investment recommendations. Local taxes, rental rules and ownership costs vary.
1. Understand the Four Main Measures
| Measure | Calculation | What it helps explain |
| Gross rental yield | Annual scheduled rent ÷ purchase price | Rent relative to price before expenses |
| Net operating income, or NOI | Effective operating income − operating expenses | Property operations before financing |
| Capitalization rate | Annual NOI ÷ property price or value | Operating income relative to the stated valuation |
| Cash-on-cash return | Annual cash flow ÷ cash invested | Cash generated relative to your cash contribution |
Definitions and expense treatment can vary between reports. State your assumptions before comparing figures.
A property can have an attractive gross yield and still produce negative cash flow after financing.
2. Start With Scheduled Rent
Suppose a property has:
- Purchase price: $200,000.
- Scheduled monthly rent: $1,800.
Annual scheduled rent is:
$1,800 × 12 = $21,600.
Gross rental yield is:
$21,600 ÷ $200,000 × 100 = 10.8%.
That figure excludes vacancy and every ownership expense.
It is an initial screening measure, not the return you can expect to spend.
If you use total acquisition cost instead of purchase price, label the denominator clearly. Otherwise, two properties can appear comparable when they are not.
3. Allow for Vacancy and Collection Losses
Scheduled rent assumes the property is occupied and payments are collected.
For this example, use a combined vacancy and collection-loss allowance of 5%:
$21,600 × 5% = $1,080.
Effective annual rental income becomes:
$21,600 − $1,080 = $20,520.
The 5% assumption is illustrative. It is not a universal allowance.
Investigate the property’s actual history, local demand, tenant turnover and any existing arrears. Avoid subtracting a vacancy loss twice if your starting income already reflects it.
4. List Operating Expenses Separately
Using the $20,520 effective income:
| Operating expense | Annual assumption |
| Property taxes | $2,400.00 |
| Insurance | $1,200.00 |
| Management: 8% of collected rent | $1,641.60 |
| Routine maintenance | $1,800.00 |
| Owner-paid utilities and administration | $600.00 |
| Total operating expenses | $7,641.60 |
Depending on the property, additional costs may include association charges, licensing, leasing fees, landscaping, pest control or other services.
Use property-specific evidence where available. A generic expense percentage should not replace known bills.
If you plan to self-manage, compare both scenarios. Removing the management fee saves cash but does not remove the work.
5. Calculate Net Operating Income
For this guide:
NOI = effective rental income − operating expenses.
Therefore:
$20,520 − $7,641.60 = $12,878.40.
This NOI excludes mortgage principal and interest, income taxes, depreciation and the separate capital-replacement reserve introduced below.
Those exclusions matter. NOI describes operations before financing; it is not the amount available to the owner after every obligation.
6. Calculate the Cap Rate
Using purchase price as the denominator:
Cap rate = annual NOI ÷ purchase price × 100.
$12,878.40 ÷ $200,000 × 100 = approximately 6.44%.
The gross yield was 10.8%. After the modeled operating losses and expenses, the cap rate is 6.44%.
Neither figure incorporates this buyer’s mortgage payments.
When reviewing a quoted cap rate, ask:
- Is the income actual, forecast or based on assumed future occupancy?
- Are all relevant operating expenses included?
- Is the denominator purchase price or an estimated market value?
- Are the figures annualized from an unusually strong period?
- Are replacement reserves treated consistently?
A higher cap rate does not automatically mean a better investment. The assumptions and risks behind it matter.
7. Subtract Financing and Replacement Reserves
Assume annual mortgage principal and interest payments of $12,000.
Also assume you set aside $1,200 annually for future major replacements.
| Cash-flow calculation | Annual amount |
| Net operating income | $12,878.40 |
| Mortgage principal and interest | −$12,000.00 |
| Capital-replacement reserve contribution | −$1,200.00 |
| Cash available after these allocations | −$321.60 |
Monthly average:
−$321.60 ÷ 12 = −$26.80.
Despite the 10.8% gross yield, the modeled property requires a small additional cash contribution.
The reserve contribution is money retained for future work, not necessarily an expense incurred that year. Showing it separately makes the cash-planning assumption clear.
Avoid Counting Escrowed Costs Twice
If a mortgage payment includes property taxes or insurance already listed as operating expenses, separate those components.
In this example, the $12,000 financing figure includes principal and interest only.
8. Calculate Cash-on-Cash Return
Suppose the buyer contributes:
| Initial cash item | Amount |
| Down payment | $40,000 |
| Closing costs | $5,000 |
| Initial work | $6,000 |
| Starting cash reserve | $4,000 |
| Total cash committed | $55,000 |
Using cash flow after the annual reserve contribution:
Cash-on-cash return = −$321.60 ÷ $55,000 × 100 = approximately −0.58%.
This is a clearly defined planning measure, not a complete investment return.
It excludes property value changes, mortgage principal reduction, sale costs and income-tax effects.
Some analyses exclude starting reserves from cash invested or calculate cash flow before replacement reserves. Check the convention before comparing results.
9. Do Not Confuse Principal Reduction With Spendable Cash
Part of a mortgage payment may reduce the loan balance.
That can increase your equity, assuming other factors remain unchanged, but it does not put money into your bank account.
Track these separately:
| Component | Spendable cash now? |
| Rent remaining after all cash obligations | Potentially |
| Mortgage principal paid down | No |
| Estimated property appreciation | No |
| Money allocated to future replacements | Already reserved |
| Possible proceeds from a future sale | Not yet realized |
A property may build equity while requiring ongoing cash contributions. Whether that is acceptable depends on the investor’s finances and risks.
10. Estimate the Rent Needed to Cover the Plan
You can calculate a break-even rent under simplified assumptions.
In the example:
- Annual operating expenses excluding percentage-based management: $6,000.
- Annual mortgage principal and interest: $12,000.
- Annual replacement reserve: $1,200.
- Vacancy and collection-loss rate: 5%.
- Management fee: 8% of collected rent.
Use:
Required monthly rent = fixed annual outflows ÷ [12 × (1 − vacancy rate) × (1 − management rate)].
Therefore:
$19,200 ÷ [12 × 0.95 × 0.92] = approximately $1,830.66 per month.
This is slightly above the assumed $1,800 rent.
The formula assumes the other costs remain fixed. It does not establish that the market will support the required rent or that a rent increase would be legally permitted.
11. Stress-Test the Property
A narrow positive result can disappear when assumptions change.
Using the same property, compare:
| Scenario | Approximate annual cash flow after financing and reserve |
| Base case | −$321.60 |
| Vacancy and collection loss rises to 10% | −$1,315.20 |
| Annual insurance increases by $600 | −$921.60 |
| Routine maintenance is $1,200 above the estimate | −$1,521.60 |
Each scenario changes one assumption independently.
Also test a combination of problems. A vacancy period and a repair can occur together.
An annual average does not show the timing of expenses. A large repair may require cash before later rental income arrives.
12. Evaluate Major Replacements Separately
Routine maintenance and major replacements serve different purposes.
A small repair may belong in the annual maintenance budget. Replacing a roof, heating system or other major component may require separate planning.
Record:
- Current condition.
- Estimated remaining useful life.
- Inspection findings.
- Replacement estimates.
- Existing reserves.
- The consequences of an earlier failure.
A $1,200 annual reserve does not guarantee that a property’s replacement needs are funded. The appropriate amount depends on the building.
Do not subtract a reserve contribution and then treat spending the same reserved money as an additional reserve contribution. Distinguish actual capital spending from transfers into savings.
13. Copy This Rental Property Worksheet
| Item | Property A | Property B |
| Purchase price | ||
| Closing and acquisition costs | ||
| Initial repairs | ||
| Starting reserves | ||
| Total initial cash committed | ||
| Scheduled monthly rent | ||
| Annual scheduled rent | ||
| Vacancy and collection-loss assumption | ||
| Effective rental income | ||
| Property taxes | ||
| Insurance | ||
| Management | ||
| Routine maintenance | ||
| Association charges | ||
| Owner-paid utilities and other expenses | ||
| Net operating income | ||
| Cap rate and denominator used | ||
| Annual mortgage principal and interest | ||
| Capital-replacement reserve contribution | ||
| Annual cash flow after reserve allocation | ||
| Cash-on-cash return and definition used | ||
| Adverse-scenario cash flow |
Attach evidence to the important assumptions: quotes, bills, inspection findings and comparable rents.
Frequently Asked Questions
Is rental yield the same as profit?
No. Gross yield compares rent with property price before expenses. Profit and cash flow require additional calculations.
Does the mortgage payment belong in NOI?
Under the definition used here, mortgage principal and interest are excluded from NOI and deducted later when calculating cash flow.
What is a good cap rate?
There is no universal answer. Location, condition, tenant risk, income assumptions and market conditions affect how a cap rate should be interpreted.
Can a property with negative cash flow still rise in value?
Yes, but appreciation is uncertain and does not automatically solve current cash requirements.
Should I include my own management time?
At minimum, track it. A self-managed property may look better on a cash basis while requiring substantial owner effort.
Is the lender’s rental-income calculation my investment forecast?
Not necessarily. Loan-qualification methods serve a lending purpose and may use standardized assumptions. Build a separate property-specific operating budget.
What should I verify before relying on this analysis?
Confirm rent evidence, financing terms, insurance, taxes, property condition, recurring charges and local rental requirements. Update the worksheet when those inputs change.
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