Rental Property Cash Flow Calculator: Is That Deal Actually Profitable?

The $2,200 rent check looks good. Then you run the full numbers.

Mortgage payment: $1,678. Property tax: $275. Insurance: $125. Vacancy allowance (8%): $176. Maintenance reserve (1% of value): $250. Property management (10%): $202. Total expenses: $2,706.

Monthly cash flow: negative $482.

This is not unusual. Most residential rental properties in expensive markets have negative or near-zero cash flow. Understanding the full expense picture before buying separates investors who build wealth from those who don't.

The Full Cash Flow Formula

Monthly Cash Flow = Gross Rent - Vacancy Loss - Operating Expenses - Debt Service

Gross Rent: Market rent, not your wishful number. Use current comparable rentals.

Vacancy Loss: Even good properties sit empty between tenants. Budget 5-10% of annual rent. On $2,200/month rent, 8% vacancy = $176/month reserved.

Operating Expenses:

• Property taxes (county assessor website)
• Homeowner's insurance (rental policies cost 15-25% more than primary home)
• Property management (8-12% of collected rent)
• Maintenance and repairs (1-2% of property value annually)
• HOA fees if applicable
• Accounting, legal

Debt Service: Monthly mortgage payment. With 20-25% down at current rates, this is often the largest expense.

Worked Example: $300,000 Rental Property

Purchase price: $300,000. Down payment: $60,000 (20%). Loan: $240,000 at 7.5% for 30 years.

| Revenue | Monthly | |---------|---------| | Gross rent | $2,200 | | Vacancy (8%) | -$176 | | Effective gross income | $2,024 |

| Expense | Monthly | |---------|---------| | Mortgage (P&I) | $1,678 | | Property tax | $275 | | Insurance | $125 | | Maintenance (1%/year) | $250 | | Management (10%) | $202 | | CapEx reserve | $100 | | Total expenses | $2,630 |

Monthly Cash Flow: -$606

This is a negative cash flow property. In San Francisco, Seattle, or Boston, deals like this are common. Investors buy them for appreciation, not cash flow.

The 1% Rule in 2026

The 1% rule says monthly rent should equal at least 1% of the purchase price. A $300,000 property needs $3,000/month rent to pass.

In most major markets in 2026, a $300,000 property rents for $1,800-$2,200. The 1% rule rarely applies in high-cost areas. It works in Cleveland, Memphis, St. Louis, and parts of the Midwest and Southeast.

If 1% is not achievable, use detailed cash flow modeling. Some deals make sense below 1% if appreciation and tax benefits are strong.

Cash-on-Cash Return

Cash-on-cash return measures annual cash flow against your actual investment.

Cash-on-Cash = Annual Cash Flow / Total Cash Invested

Example: $400/month cash flow, $75,000 cash invested (down payment + closing + initial repairs).

• Annual cash flow: $4,800
• Cash-on-cash: $4,800 / $75,000 = 6.4%

Real estate investors typically target 6-12% cash-on-cash. The current rate environment makes this harder to achieve than it was in 2015-2020.

The Four Return Drivers

Negative cash flow does not necessarily mean a bad deal. Total return includes:

1. Cash flow (or negative cash flow as a cost)
2. Appreciation
3. Debt paydown (tenants pay down your loan)
4. Tax benefits (depreciation)

See Best Investing Platforms for real estate investment platform alternatives (REITs) if you want real estate exposure without management.

Use the CalcMoney Investment Return Calculator to model total return including all four drivers for any specific deal.

Frequently Asked Questions

What is a good cap rate for rental property?

Cap rate = Net Operating Income / Property Value. Typical ranges: 5-7% in suburban markets, 3-5% in major metros, 7-10% in smaller cities. Higher cap rates mean more cash flow relative to price but often signal slower appreciation and more management intensity.

Should I hire a property manager or self-manage?

Management costs 8-12% of collected rent. On $2,200/month, that is $2,112-$3,168 per year. Self-management saves this but requires time for tenant screening, maintenance coordination, and occasional crises. Most long-distance investors use professional management.

How does depreciation work on rental property?

The IRS allows you to deduct the building portion of a rental property over 27.5 years. On a $300,000 property where $220,000 is the building, annual depreciation is $8,000. This paper deduction reduces taxable rental income and can shelter other passive income, subject to passive activity loss rules.