# Rental vacancy cost calculator

Updated 2026-09-26.

Enter your average rent, how long units sit empty between tenants and how many turnovers you run a year. The calculator shows the rent lost per empty day, per turnover and per year.

## What to count as empty

Count only the days no one pays rent: from the day after the last tenant's paid period ends to the day before the next tenant's rent starts. A day the unit is empty but still paid for is not lost rent.

Use the rent the next tenant pays if it differs from the last. If you do not have your own figures, CMHC publishes average rents by city in its rental market data tables.

## What it leaves out

Lost rent only. Utilities you carry while the unit is empty, the turnover work, advertising and leasing fees are separate costs. Add them from your own ledger.

To lay the work out against the dates, use the [turnover planner](https://roundhousegroup.ca/tools/turnover-planner/). For the order the work runs in, see the [rental turnover checklist](https://roundhousegroup.ca/answers/rental-turnover-checklist/).

## Method

Rent per day is the monthly rent times 12, divided by 365. Rent lost per turnover is rent per day times the days empty. Rent lost per year is rent lost per turnover times the turnovers a year. Each figure is rounded to the cent at the end, not along the way.

## Worked example

An average rent of $2,400 a month is $78.90 a day: $2,400 x 12 / 365 = $78.904. A unit empty 21 days loses $1,656.99 in rent. Twelve turnovers a year at that rent and length lose $19,883.84.

## Questions

### Why divide by 365 and not by 30?

A month runs 28 to 31 days. Twelve months of rent over 365 days gives the same daily figure in every month, so a February vacancy and an August one compare on the same basis.

### Should a leap year use 366 days?

The calculator uses 365 in every year. Dividing by 366 instead lowers the daily figure by about 0.27 percent.

### Does Roundhouse see the rent I enter?

No. The page does the arithmetic in your browser. Nothing is sent to Roundhouse or stored on a server.

## Sources

- [CMHC, rental market data tables (average rents by city)](https://www.cmhc-schl.gc.ca/professionals/housing-markets-data-and-research/housing-data/data-tables/rental-market)

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