Rental property
Rental cash flow and cap rate calculator
Estimate net operating income, cap rate, cash flow after debt service, and cash-on-cash return. Use it to screen a purchase or to sanity-check a property you already own. Figures stay on this device.
How to use this calculator
- Enter the purchase price and the total monthly rent you expect if the property is fully occupied.
- Set a vacancy rate. Then add annual operating expenses. Management, if you use it, is taken as a percentage of income after vacancy.
- Either enter a loan so the calculator can build a standard fixed-rate payment, or type the monthly principal-and-interest payment you already have.
- If you care about cash-on-cash return, enter the cash you will actually put in: down payment, closing costs, and any upfront rehab.
The output is a one-year snapshot at the numbers you typed. It does not inflate rent, recast a loan, or model depreciation or income taxes. Those belong in a fuller projection or in a year-round tracker.
Track the real year, not just the pro forma
The Rental Tracker spreadsheet ($12) is a downloadable workbook for recording rent and expenses as they happen, with a dashboard and a Schedule E-style summary. This calculator does not replace that record.
Frequently asked questions
How do you calculate cap rate?
Capitalization rate is net operating income divided by the property’s value (or purchase price, if you leave the value blank). NOI is effective rental income after vacancy, minus operating expenses. Mortgage payments are not subtracted when figuring NOI or cap rate, because cap rate describes the property unlevered.
Why isn’t the mortgage included in NOI?
NOI measures the property’s operating performance before financing. Two buyers can pay the same price and have the same NOI, but very different cash flow, depending on their down payment and interest rate. Cash flow (NOI minus annual debt service) and cash-on-cash return show the effect of the loan.
Should vacancy be a percentage of rent?
This calculator treats vacancy as a percentage of gross scheduled rent, which is a common planning shorthand. Use a rate that matches the property’s market and your actual turn time—not zero, unless you have a firm reason. Property management is then applied to effective gross income (rent after vacancy).
What expenses belong in operating expenses?
Include recurring costs to keep the property rented: property taxes, insurance, maintenance and repairs you expect in a normal year, HOA dues, owner-paid utilities, and management. Capital improvements (a new roof, a renovation) and mortgage principal are not operating expenses. If you want a conservative maintenance estimate, many investors start around 5–10% of effective income and then replace that with real numbers.
Is a high cap rate always better?
Not by itself. A higher cap rate can mean more income relative to price, or it can mean the market is pricing in more risk, more deferred maintenance, or weaker rent growth. Use this as a screening number, then underwrite the actual lease, condition, and local market.
Does this replace a full rental tracker?
No. This page is for a quick underwriting snapshot. It does not produce a Schedule E summary, store a year of transactions, or keep records for your tax preparer. If you already own the property, a spreadsheet log is the better tool for that.