How to calculate investment property cash flow
A practical guide for real estate investors on calculating monthly cash flow, which costs not to overlook, and why rent alone is not enough.
Cash flow is the monthly difference between what a property earns and what it actually costs. For an investment apartment, it determines whether the portfolio can handle tenant vacancies, rising interest rates, or unexpected repairs.
The basic formula
The simplest calculation is: monthly rent minus mortgage payment minus regular monthly costs minus reserves for annual and irregular expenses.
If you rent out an apartment for EUR 850, the mortgage is EUR 520, management and utilities EUR 140, and monthly reserve EUR 80, net cash flow is approximately EUR 110 per month.
Costs investors often underestimate
The most common mistake is counting only rent and mortgage payment. Such a calculation looks good on paper but does not capture the reality of ownership.
- repair fund, building management and owner-paid utilities,
- property and home insurance,
- property tax and local fees,
- vacancy periods, marketing and minor repairs,
- reserve for appliance replacement or major technical work.
Why track cash flow continuously
Cash flow is not a one-time calculation at purchase. It changes with rate resets, rent adjustments, renovations, and rising operating costs.
Wismeo is designed precisely to let investors see cash flow across their entire portfolio, not just in a single spreadsheet at purchase.
Want to keep these numbers under control?
Wismeo helps track cash flow, mortgages, yields and property portfolio documents in one place.
View Wismeo