About the Vacancy Rate Calculator
Every empty unit or empty month is rent you never collect. This vacancy rate calculator measures that loss two ways. Physical vacancy is the share of units (or days) that sit empty. Economic vacancy goes further and also counts rent concessions and bad debt — the income you lose even when a unit is occupied — so it shows how much of your potential rent actually reaches your bank account.
Use the by-units mode for an apartment building or portfolio: enter the total units, the average number vacant over the period, the average rent and the length of the period. Use the by-days mode for a single-family rental or one unit: enter how many days it sat empty during the period. In both modes you can add concessions (free months, move-in specials) and bad debt.
The results feed straight into a rental analysis: potential gross rent minus vacancy loss, concessions and bad debt is your effective gross income, the top line of net operating income. Days mode uses a daily rent of monthly rent × 12 ÷ 365.
With the default inputs, the physical vacancy rate is 10%. Change any value above to recalculate instantly.
How to use the vacancy rate calculator
- 1Choose whether to measure by units (building) or by days (one unit).
- 2Enter the units and average vacant units, or the days vacant and days in the period.
- 3Enter the average monthly rent per unit.
- 4Add concessions and bad debt to see economic vacancy.
- 5Use the effective gross income in your NOI or cap rate analysis.
Formula and method
Physical vacancy counts how much of the property is empty: average vacant units divided by total units for a building, or days vacant divided by days in the period for a single unit. Occupancy is 100% minus vacancy. Vacancy loss is the rent those empty units or days would have earned at the average rent.
Economic vacancy compares what you actually collect with potential gross rent — every unit leased at full rent for the whole period. It adds concessions and uncollected rent to vacancy loss, so it is always at least as high as physical vacancy. Effective gross income is potential rent minus all three losses and is the starting point for net operating income.
- PGR
- Potential gross rent: units × rent × months
- EGI
- Effective gross income after vacancy, concessions and bad debt
Worked examples
20-unit building with 2 units empty on average
Two of 20 units empty is 10% physical vacancy. At $1,500 rent for 12 months that is $36,000 lost from $360,000 of potential rent. Adding $3,000 of concessions and $2,000 of bad debt leaves $319,000 collected — an economic vacancy of about 11.4%.
Single-family home empty 45 days between tenants
Forty-five empty days out of 365 is a 12.3% vacancy rate. At $1,800 a month the daily rent is about $59.18, so the turnover cost $2,663 of the $21,600 potential rent.
Frequently asked questions
How do you calculate vacancy rate?+
Divide the number of vacant units by the total number of units and multiply by 100. For a single rental, divide the number of days it sat empty by the days in the period. Occupancy rate is 100% minus the vacancy rate.
What is a good vacancy rate for a rental property?+
It depends on the market and property type. Many investors budget 5%–8% vacancy for residential rentals; a rate consistently well above the local average suggests pricing, condition or management problems.
What is the difference between physical and economic vacancy?+
Physical vacancy measures empty units. Economic vacancy measures lost income, including concessions and unpaid rent from occupied units, so it shows how much of your potential rent you actually collect.
What vacancy rate should I use when analyzing a deal?+
Use the local rental vacancy rate for similar properties, adjusted for your expected turnover. Even a fully leased single-family home should budget for vacancy between tenants, often two to four weeks a year.
Where can I find vacancy rates for my area?+
The US Census Bureau publishes national and regional rental vacancy rates through its Housing Vacancies and Homeownership survey. Local property managers and listing data give more specific figures.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.