Vacancy Rate Calculator
Enter the number of units, how many are vacant and the average monthly rent. You get the vacancy rate, the occupancy rate, the rent collected and the rent lost per month and per year. Nothing is sent anywhere.
In one sentence: Vacancy rate is the share of units standing empty, and lost rent is what that share costs.
Formula: vacancy rate = vacant units ÷ total units × 100; occupancy = 100 − vacancy; lost rent per month = vacant units × average rent; per year = × 12; collected = occupied units × average rent.
Physical and economic vacancy
This calculator measures physical vacancy: units with nobody in them. Economic vacancy is wider and includes units occupied by tenants who are not paying, units let below market and units used free by staff. Lenders and buyers look at economic vacancy, which is why the rent collected line matters as much as the rate. For a single property over time, count vacancy in months: a unit empty for one month in a year is an 8.3% vacancy for that unit, and the cap rate calculator takes that figure as its vacancy allowance.
What drives the rate
Turnover is the main cause: every move-out produces at least a few days empty for cleaning and viewings, and often weeks. Lowering the vacancy rate is therefore mostly about keeping good tenants, which is why a modest rent increase that keeps a tenant usually beats a larger one that loses them; the rent increase calculator shows the trade-off. Pricing above market, slow repairs and slow re-letting add to it. A vacancy rate well below the local average may also mean rents are set too low.
Budgeting for it
No building runs at 100% occupancy for long, so budgets should assume a vacancy allowance rather than full rent. The rent-lost-per-year line converts the current rate into the amount to plan for, and the rental cash flow calculator applies the allowance to a single property's monthly figures.
Frequently asked questions
Can I use this for rooms, beds or desks?
Yes. Any countable rentable unit works; use the average rent per unit of that type.
How do I handle units of different rents?
Use the average rent for the rate and lost rent, or run the calculator once per rent band and add the results.
Is my data stored?
No. Everything runs in your browser.