Rental Cash Flow Calculator
Calculate monthly rental property cash flow from rent, mortgage, taxes, insurance, and maintenance.
Formula
Monthly Cash Flow = Effective Rent - (Mortgage + Taxes + Insurance + Maintenance + Management + HOA + Utilities)
Effective rent is gross rent reduced by the vacancy rate. Cash flow subtracts all monthly expenses from effective rent. Cap rate divides annual NOI (excluding mortgage) by purchase price. Cash-on-cash return divides annual cash flow by total cash invested. DSCR divides NOI by annual mortgage payments.
Worked Examples
Example 1: Single Family Rental with Positive Cash Flow
Problem: A $300,000 home purchased with $60,000 down, renting at $2,000/month. Mortgage $1,200, taxes $250, insurance $120, maintenance $150, no management. 5% vacancy.
Solution: Effective rent: $2,000 x 0.95 = $1,900\nTotal expenses: $1,200 + $250 + $120 + $150 = $1,720\nMonthly cash flow: $1,900 - $1,720 = $180\nAnnual cash flow: $2,160\nNOI: ($1,900 - $520) x 12 = $16,560\nCap rate: $16,560 / $300,000 = 5.52%\nCash-on-cash: $2,160 / $60,000 = 3.60%
Result: Cash Flow: $180/mo ($2,160/yr) | Cap Rate: 5.52% | Cash-on-Cash: 3.60%
Example 2: Duplex with Property Management
Problem: A $400,000 duplex with $100,000 down, total rent $3,200/month. Mortgage $1,800, taxes $400, insurance $180, maintenance $200, management $320 (10%), HOA $100. 7% vacancy.
Solution: Effective rent: $3,200 x 0.93 = $2,976\nTotal expenses: $1,800 + $400 + $180 + $200 + $320 + $100 = $3,000\nMonthly cash flow: $2,976 - $3,000 = -$24\nAnnual cash flow: -$288\nNOI: ($2,976 - $1,200) x 12 = $21,312\nCap rate: $21,312 / $400,000 = 5.33%\nCash-on-cash: -$288 / $100,000 = -0.29%
Result: Cash Flow: -$24/mo (-$288/yr) | Cap Rate: 5.33% | Cash-on-Cash: -0.29%
Frequently Asked Questions
What is rental property cash flow and why does it matter?
Rental property cash flow is the net amount of money generated by a rental property after all income is collected and all expenses are paid. Positive cash flow means the property generates more income than it costs to own and operate, providing passive income that can supplement your salary, fund retirement, or be reinvested. Negative cash flow means you are subsidizing the property from your own pocket each month, which may be acceptable if the property is appreciating significantly but is generally unsustainable long-term. Cash flow is considered the most reliable indicator of rental property performance because unlike appreciation, which is speculative, cash flow is measurable and predictable. Most experienced real estate investors prioritize cash flow over appreciation when evaluating properties because consistent positive cash flow provides financial security regardless of market conditions.
How do I calculate net operating income for a rental property?
Net operating income is calculated by subtracting all operating expenses from the effective gross income, excluding mortgage payments because NOI measures the property's performance independent of financing. Start with gross rental income and subtract vacancy and credit loss allowances to get effective gross income. Then subtract all operating expenses including property taxes, insurance, maintenance and repairs, property management fees, HOA dues, utilities paid by the landlord, landscaping, pest control, and accounting fees. Do not include mortgage principal and interest, income taxes, depreciation, or capital improvements in the NOI calculation. For example, a property renting for $2,000 per month with 5 percent vacancy generates $22,800 in effective annual income. If operating expenses total $8,400 per year, the NOI is $14,400. NOI is used to calculate the capitalization rate and debt service coverage ratio.
What is a good cap rate for a rental property?
A good capitalization rate depends on the property type, location, condition, and your investment goals. In general, cap rates of 4 to 6 percent are found in stable, appreciating markets like major metropolitan areas where properties hold their value and attract quality tenants. Cap rates of 7 to 10 percent typically indicate higher-yield properties in secondary markets or less desirable neighborhoods, offering better cash flow but potentially higher risk and less appreciation. Cap rates above 10 percent may signal distressed properties, difficult locations, or deferred maintenance that could require significant investment. Comparing cap rates should only be done between similar property types in similar locations because a 5 percent cap rate in San Francisco represents a very different risk profile than a 5 percent cap rate in a small rural town. The best cap rate for you balances your cash flow needs with your risk tolerance and appreciation expectations.
What is the cash-on-cash return and how does it differ from cap rate?
Cash-on-cash return measures the annual cash flow relative to the actual cash you invested, including down payment, closing costs, and any renovation expenses. Unlike the cap rate which ignores financing, cash-on-cash return reflects the impact of leverage on your returns. If you invest $60,000 as a down payment and the property generates $4,800 in annual cash flow after all expenses including mortgage payments, your cash-on-cash return is 8 percent. The same property might have a cap rate of only 5 percent, but leverage amplifies your return on invested capital. A good cash-on-cash return is generally 8 to 12 percent, though many investors accept lower returns in appreciating markets. Cash-on-cash return can be negative if the property has negative cash flow, even if the cap rate is positive, because the mortgage payment exceeds the NOI.
How should I estimate maintenance and repair costs for a rental property?
There are several methods to estimate maintenance costs, and experienced investors often use multiple approaches and take the highest estimate. The one percent rule suggests budgeting 1 percent of the property value annually for maintenance, so a $300,000 property should budget $3,000 per year or $250 per month. The square footage method budgets $1 to $2 per square foot annually, so a 1,500 square foot property would need $1,500 to $3,000 per year. The 50 percent rule is a comprehensive approach where total operating expenses including maintenance, taxes, insurance, and management should equal approximately 50 percent of gross rent. Newer properties in good condition may need less, while older properties or those with aging systems may need significantly more. Creating a capital expenditure reserve for major items like roof replacement, HVAC systems, and water heaters is essential beyond routine maintenance budgeting.
What vacancy rate should I use for rental property analysis?
The vacancy rate you use should reflect local market conditions rather than a generic national average. In high-demand rental markets with low housing supply, vacancy rates can be as low as 2 to 3 percent, meaning your property might sit empty for only one to two weeks between tenants. In average markets, 5 to 7 percent is a reasonable assumption, accounting for approximately two to three weeks of vacancy per year plus occasional longer gaps between tenants. In softer rental markets or for properties in less desirable locations, use 8 to 12 percent or higher. Check local vacancy data from the Census Bureau, property management companies, or online rental platforms for your specific area. Also consider seasonal factors because properties in college towns have predictable summer vacancies, while vacation rental areas have seasonal demand patterns. Using too low a vacancy rate is one of the most common mistakes in rental property analysis.