Vacancy Rate Calculator

A vacancy rate is a percentage, and a percentage alone does not pay a mortgage. This calculator works out that percentage three ways, by units, by lost revenue, or by vacant unit-days, then converts it into occupancy and dollars lost, with a health rating set for your property type. If you already know your rate and want the full dollar picture, including turnover costs and whether a rent cut would pay off, use the vacancy rent calculator instead.

Quick Answer

How to Use the Vacancy Rate Calculator

Pick the method that matches the records you actually have, fill in that panel, then set the property type and, if you want dollars, the gross potential annual rent before you calculate. Unit counts suit a quick snapshot, revenue suits an annual review, and unit-days suit any period where units sat empty for part of the time.

1. By Units: enter total units and vacant units. Best for a today snapshot of a building or small portfolio.
2. By Revenue: enter total potential annual revenue and the revenue lost to vacancy. Best when concessions, partial vacancies, or unpaid rent matter, because this is the economic view.
3. By Time: pick the period, then enter total unit-days available (units x days) and vacant unit-days. Best for seasonal properties and for comparing periods of different lengths.
4. Set property type and rent: the property type only changes the rating bands, never the rate. The optional rent field only converts the finished rate into dollars lost per year and month.

Two input habits matter. Counts are read as whole numbers, so 4.9 vacant units is treated as 4. And the tool rejects negative vacant counts and lost revenue outright, and checks that vacant amounts stay at or below their totals, so a stray minus sign now stops the calculation instead of producing a negative rate.

The Three Vacancy Formulas

Each method divides what was empty by what could have been filled, then multiplies by 100. They differ only in what counts as empty: units, dollars, or days.

• Physical vacancy = Vacant units / Total units x 100
• Economic vacancy = Lost revenue / Total potential revenue x 100
• Time-based vacancy = Vacant unit-days / Total unit-days x 100
• Occupancy rate = 100% − Vacancy rate
• Income lost = Gross potential rent x Vacancy rate

The denominator discipline is where most hand calculations go wrong. Revenue lost must cover the same period and the same units as total potential revenue, and unit-days must cover the same window as the period you pick. Mix a quarter of losses with a year of potential revenue and the rate comes out four times too small. Lender underwriting keeps the same discipline: Fannie Mae multifamily guidance builds gross potential rent from the rent roll, then deducts physical vacancy, concessions, and bad debt as separate lines to reach net rental income, which is exactly the split the revenue method mirrors.

Worked Example: One Building, Three Methods, One Answer

Take a 50-unit residential building where each unit rents for $1,500 a month. Gross potential rent is 50 x $1,500 x 12 = $900,000 a year, and 4 units stand vacant.

Method	Inputs	Math	Rate
By Units	4 vacant of 50 total	4 / 50 x 100	8.00%
By Revenue	$72,000 lost of $900,000 potential	72,000 / 900,000 x 100	8.00%
By Time	1,460 vacant unit-days of 18,250	1,460 / 18,250 x 100	8.00%

All three agree here because the vacancy is clean: whole units, empty for the whole year, at full rent. The tool returns 8.00% vacancy, 92.00% occupancy, a Good rating for residential, and, with the $900,000 rent field filled, $72,000 lost per year and $6,000 per month. When your three methods disagree on a real property, that disagreement is the finding: revenue vacancy running ahead of unit vacancy points at concessions or below-market leases, and time vacancy running ahead points at slow turns concentrated in a few units. Comparing the result with the plain occupancy percentage calculator is a useful sanity check, since occupancy here is simply 100 minus the rate.

What Counts as a Good Vacancy Rate Depends on the Property

There is no single good rate, which is why the tool rates the same percentage differently across six property types. The bands below are the exact thresholds the rating uses.

Property type	Excellent	Good	Needs attention
Residential / multifamily	5% or less	Over 5% to 10%	Over 10%
Office	8% or less	Over 8% to 15%	Over 15%
Retail	6% or less	Over 6% to 12%	Over 12%
Industrial	5% or less	Over 5% to 10%	Over 10%
Student housing	3% or less	Over 3% to 8%	Over 8%
Senior housing	4% or less	Over 4% to 9%	Over 9%

For outside context, the Census Bureau put the national rental vacancy rate at 7.3% in the second quarter of 2026, with regional rates running from 5.3% in the West to 9.5% in the South. HUD market profiles use a similar reality check from the other direction, treating an apartment property as stabilized once occupancy reaches 90% or better. Treat the bands and the national figure as starting points: your submarket, building class, and lease-up stage should move the target, not the headline average. Once you have a rate you trust, the gross potential rent calculator helps you pin down the full-occupancy rent figure the dollar conversion depends on.

Physical vs Economic Vacancy: Why the Two Rates Diverge

Physical vacancy counts empty space. Economic vacancy counts missing money, and the two part company whenever a unit is occupied but not paying full freight.

A unit given to an on-site manager, a month of free rent used to close a lease, or a long-term tenant paying a 2019 rent in 2026 all show as occupied in a unit count and as lost income in a revenue count. Delinquent rent does the same. That is why investors who only count doors routinely understate their problem, and why the economic occupancy calculator exists as a companion measure. Neither rate is the true one. The unit rate tells you about leasing and condition, the revenue rate tells you about cash, and the gap between them tells you how much of your loss is pricing and concessions rather than emptiness.

What Competing Vacancy Rate Calculators Miss

Most vacancy tools in the search results stop at one division: vacant units over total units, with a percentage and little else. One widely used rival adds occupied units and a vacancy ratio, which is the same division restated. A stronger rental analyzer adds break-even occupancy and cash flow at several vacancy levels, but it still models physical vacancy only and asks for your full expense stack before it says anything useful.

What none of them combine on one page is what this tool does: three methods that cross-check each other, an economic method that captures concessions and delinquency, a conversion into dollars lost per year and per month, and a rating whose bands change across six property types instead of grading an office building by apartment rules. The honest limit is scope. This page rates the percentage; it does not model turnover costs, rent-cut decisions, or full cash flow, and it will not tell you what your building is worth. For the value angle, vacancy feeds net operating income, and income divided by a cap rate is where a few points of vacancy turn into a five-figure change in value.

When a Very Low Vacancy Rate Is Its Own Warning

A rate at or near zero deserves a second look, not a celebration. If every unit fills within days at the asking rent, the asking rent is probably below market, and the income given up on every occupied unit can quietly exceed what a normal vacancy would have cost.

The practical test is speed. Units that lease in under a week, with multiple qualified applicants, are priced soft. Test a modest increase on the next turn rather than across the whole building, watch days on market, and compare the gain against the risk of extra vacant days using the time method. The goal is not the lowest possible vacancy rate. It is the rate, usually somewhere in the Good band for your property type, where total collected rent is highest.

Frequently Asked Questions

Add This Calculator to Your Website

References