Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Annual vacancy loss
$9,408
Potential gross rent (100% occupied)
$134,400
Expected collected rent
$124,992
Loss above market vacancy assumption
$2,688
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How to use this
- 1Enter number of units.
- 2Enter average monthly rent per unit ($).
- 3Enter vacancy rate (%).
- 4Enter market / target vacancy rate (%).
- 5Read your annual vacancy loss on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
Vacancy loss is the gap between potential gross rent (every unit rented 100% of the time at market rent) and what you actually collect. This is different from turnover cost, which includes make-ready and marketing — vacancy loss is purely the rent that never got collected. Lenders and appraisers use a vacancy assumption (commonly 5-8% for stabilized multifamily, higher for single-family or student housing) to underwrite NOI, and if your actual vacancy runs above that assumption, your property is underperforming its appraisal even if every other expense line is on budget.
Worked example
Using the values the calculator loads with:
Inputs
- Number of units: 8
- Average monthly rent per unit: 1400 $
- Vacancy rate: 7 %
- Market / target vacancy rate: 5 %
Results
- Annual vacancy loss: $9,408
- Potential gross rent (100% occupied): $134,400
- Expected collected rent: $124,992
- Loss above market vacancy assumption: $2,688
What each field means
Inputs
- Number of units
- The number of units used in the calculation. Starts at 8 so you have a working example on load.
- Average monthly rent per unit ($)
- The average monthly rent per unit used in the calculation, measured in $. Starts at 1400 $ so you have a working example on load.
- Vacancy rate (%)
- The vacancy rate used in the calculation, measured in %. Starts at 7 % so you have a working example on load. Accepted range: 0–100 %.
- Market / target vacancy rate (%)
- The market / target vacancy rate used in the calculation, measured in %. Starts at 5 % so you have a working example on load. Accepted range: 0–100 %.
Results
- Annual vacancy loss
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Potential gross rent (100% occupied)
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Expected collected rent
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Loss above market vacancy assumption
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What vacancy rate should I underwrite?
5-8% is standard for stable multifamily in most metros; C-class or transitional areas often run 8-12%. Single-family rentals with longer tenancies can budget as low as 4-5%, but always look at your submarket's actual data rather than a national average.
Is vacancy loss the same as credit loss?
No. Vacancy loss is rent lost from empty units. Credit loss is rent lost from occupied units where the tenant doesn't pay — skips, evictions, and write-offs. A full pro forma income statement should show both lines separately.
How does this affect property value?
NOI drives value under the income approach, and vacancy loss directly reduces NOI. At a 6% cap rate, an extra $10,000 in annual vacancy loss versus market assumptions represents roughly $167,000 of lost value — which is why buyers scrutinize a seller's trailing vacancy closely.
How do I cut structural vacancy?
List units before the outgoing tenant leaves, keep make-ready turnaround under a week, and price at market rather than chasing last year's rent. Persistent above-market vacancy is almost always a pricing or condition problem, not a demand problem.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Rental Vacancy Loss Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/vacancy-loss-calculator
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/vacancy-loss-calculator" target="_blank" rel="noopener">Rental Vacancy Loss Calculator — RevenueLab</a> (2026).</p>
Source: [Rental Vacancy Loss Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/vacancy-loss-calculator) (2026).