Vacancy Rate Calculator

Measure how often your rentals sit empty and how much rent you are leaving on the table. Calculate both physical vacancy and economic vacancy so you can see the full impact on cash flow.

Physical vacancy

Measures how often units were empty over the period tracked.

Total units

Months tracked

months

Unit-months vacant

Average monthly rent

Economic vacancy

Compares gross potential rent with rent actually collected. Captures concessions, delinquency, and loss-to-lease.

Gross potential rent (annual)

Collected rent (annual)

Physical vacancy rate

4.17%

Occupancy rate

95.83%

Rent lost to vacancy

$3,700

Economic vacancy rate

7.55%

What the vacancy numbers tell you

Vacancy is in the typical underwriting range many lenders and investors use for stabilized rentals.

Total unit-months

Economic loss (annual)

$6,700

Collection ratio

92.5%

Physical vacancy = vacant unit-months ÷ total unit-months. Economic vacancy = (gross potential rent − collected rent) ÷ gross potential rent, which also picks up concessions, delinquency, and loss-to-lease that a pure occupancy number can hide.

How to Use

Enter the total number of units in the property or portfolio and the number of months you are measuring over.
Add the number of unit-months vacant during that window — one unit empty for three months is three unit-months.
Include average monthly rent so the calculator can translate vacant time into dollars lost.
For economic vacancy, enter gross potential rent and rent actually collected to capture concessions and delinquency.
Use the resulting physical and economic vacancy rates when underwriting cap rate, cash flow, and DSCR.

Frequently Asked Questions

What is the difference between physical and economic vacancy?

Physical vacancy measures time with no tenant. Economic vacancy measures the rent you would have collected if every unit were fully paying market rent. Economic vacancy also captures concessions, delinquency, and loss-to-lease.

What is a typical vacancy rate?

Stabilized single-family and small multifamily rentals in strong markets often run 4–7% physical vacancy. Workforce housing, higher-turn markets, or older assets may underwrite at 8–12%. Lender underwriting usually floors vacancy at 5–7% even when history is lower.

How do I calculate unit-months vacant?

Add up the months each unit was empty during the measurement period. For example, one unit vacant 1 month plus another vacant 2 months is 3 total unit-months vacant, regardless of portfolio size.

Why does economic vacancy matter for underwriting?

A property can be 100% physically occupied while collecting well below market rent because of concessions, delinquency, or renewal discounts. Economic vacancy is the metric that reveals that gap and keeps cash flow projections honest.

How should I use the vacancy rate from this calculator?

Feed the higher of your historical rate and a conservative market-standard rate into cap rate, cash flow, and DSCR calculators so the deal math stays defensible if the market softens.