Property Cash Flow Calculator

Use this calculator to estimate monthly property cash flow after mortgage, expenses, and vacancy. It helps investors see whether a rental property is likely to put cash in or take cash out each month.

What this calculator does

The property cash flow calculator estimates monthly cash flow from rent after key monthly outflows.

It uses:

• monthly rent
• monthly mortgage
• monthly expenses
• vacancy rate

This gives the expected monthly cash flow after adjusting rent for vacancy.

How to use the property cash flow calculator

Enter monthly rent, monthly mortgage, monthly expenses, and vacancy rate. Vacancy rate should be entered as a percentage between 0% and 100%.

Include recurring expenses such as management, repairs, insurance, rates, and levies where relevant.

Property Cash Flow Formula

Monthly cash flow = monthly rent x (1 - vacancy rate / 100) - monthly mortgage - monthly expenses

Where vacancy-adjusted rent is the expected collected rent after allowing for empty periods.

Example calculation

If:

• Monthly rent = 3,000
• Vacancy rate = 5%
• Mortgage and expenses = 2,400
• Monthly cash flow = 450

The vacancy-adjusted rent is 2,850, leaving 450 in monthly cash flow.

What is property cash flow?

Property cash flow is the money left each month after rental income is reduced by mortgage payments and operating expenses.

Positive cash flow means the property contributes cash. Negative cash flow means the investor must fund the shortfall from other income or reserves.

Interpreting your result

Cash flow is about monthly resilience. Even a property with good long-term growth can create stress if monthly cash flow is consistently negative.

Use this result alongside yield and ROI. The ROI Calculator can help measure total return beyond monthly cash movement.

When to use this calculator

Use this calculator when you want to:

• assess monthly affordability
• compare rental deals
• test vacancy assumptions
• review debt impact

Common mistakes

Common mistakes include:

• ignoring vacancy allowance
• excluding maintenance reserves
• using annual values by accident
• treating cash flow as total return

FAQs

Can property cash flow be negative?

Yes. Negative cash flow means monthly costs exceed vacancy-adjusted rent.

Should tax be included?

This calculator focuses on pre-tax cash flow. Tax should be reviewed separately for your situation.