Vacancy rate calculator
Empty days are only half of vacancy. This counts them across every unit, then adds the free month you gave to sign a lease and the balance you never collected, and tells you what share of your potential rent actually arrived.
Pre-filled with a four-unit year: 52 empty unit-days, half a month free to sign one tenant, one unpaid balance.
Economic vacancy over 365 days, 4 units
5.47%
- Available unit-days
- 1,460
- Physical vacancy rate
- 3.56%
- Vacant unit-days ÷ available unit-days.
- Gross potential rent for the period
- $69,600.00
- Every unit let at market rent every day (rent × 12 ÷ 365 per day).
- Rent lost to empty days
- $2,478.90
- Concessions and uncollected rent
- $1,325.00
- Total rent lost
- $3,803.90
- Economic vacancy rate
- 5.47%
- Total rent lost ÷ gross potential rent.
- Rent actually collected
- $65,796.10
- Rent lost, annualised
- $3,803.90
Physical vacancy and economic vacancy are different numbers
Physical vacancy counts empty days. Economic vacancy counts lost money, and that includes rent you gave away or never collected while the unit was full. A building can show low physical vacancy and still lose real money if every lease starts with a free month or one tenant runs up a balance.
| Measure | Formula | What it tells you |
|---|---|---|
| Physical vacancy | Vacant unit-days ÷ (units × days) | How long it takes you to re-let |
| Economic vacancy | (Lost rent + concessions + bad debt) ÷ gross potential rent | What the ledger actually lost |
| Gross potential rent | Units × market rent × 12 | The ceiling, every unit let every day |
Daily rent here is monthly rent × 12 ÷ 365, so a year adds up exactly. The prorated rent calculator shows the other day-count methods a lease might use.
The default example, worked through
Four units at $1,450 a month for a year is $69,600 of gross potential rent and 1,460 available unit-days. One turnover left a unit empty for 52 days, the new tenant got half a month free, and a departing tenant left $600 unpaid.
| Line | Amount |
|---|---|
| 52 empty unit-days at $47.67 a day | $2,478.90 |
| Concession to sign | $725.00 |
| Unpaid balance written off | $600.00 |
| Rent lost | $3,803.90 |
| Physical vacancy | 3.56% |
| Economic vacancy | 5.47% |
The empty days look like 3.6%. The money says 5.5%, because the free half-month and the unpaid balance cost almost as much as the empty unit did. Keep the rent ledger current and both of those numbers come straight off it.
The national rate, and why it is not your rate
The Census Bureau put the U.S. rental vacancy rate at 7.3% for the second quarter of 2026, against 7.0% a year earlier (Housing Vacancies and Homeownership, released July 28, 2026, checked 2026-10-18). It defines that rate as "the proportion of the rental inventory which is vacant for rent."
That is a snapshot of all rental housing at one point in time. Your rate is a count of your own days and dollars over a period. Use the national figure as background. A unit that turns every two years and re-lets in three weeks will run well under it, and a building with a slow lease-up can run well over it.
Set the allowance from your own history
Run this calculator on your last two or three years, then use the economic rate as the vacancy line. With no history yet, a figure near the local market rate is a fair starting point until you have your own.
Where the number goes next
- 01Put the economic rate in the vacancy line of the cash flow calculator.
- 02Use the same rate in the cap rate calculator before you compare a listing with your own building.
- 03Carry the cash flow it produces into cash-on-cash return.
- 04Price a single move-out, with make-ready and leasing, in the turnover cost calculator. This page measures the rate across the year; that one prices one event.
Lost rent is not a tax deduction
Vacancy feels like a cost, but the IRS does not treat it as one. Publication 527 says plainly that while a property is held for rent, "you can't deduct any loss of rental income for the period the property is vacant". The ordinary expenses of keeping it ready, depreciation included, may still be deductible (IRS Publication 527, checked 2026-10-18).
Unpaid rent follows the same logic
The same publication says a cash basis taxpayer should not deduct uncollected rent, because it was never counted as income. The bad debt line above is a cash flow loss, not a deduction. More in landlord tax deductions.
The cheapest way to cut both rates is to keep the tenant you have. The lease renewal guide covers when to offer the renewal and how to price it.
Sources read for this page
- Census Bureau CPS/HVS, Q2 2026checked 2026-10-18
- Census Bureau HVS definitionschecked 2026-10-18
- IRS Publication 527 (2025)checked 2026-10-18