Strategy & Analysis6 min read

How Vacancy Rate Affects Your Rental Property Returns

Even a modest vacancy rate can significantly erode cash flow and ROI. Learn how to model vacancy into your analysis and what a realistic allowance looks like.

Vacancy is the silent killer of rental property returns. A 5% vacancy rate sounds harmless. It's just 18 days per year. But when you model it through cash flow, cap rate, and long-term IRR, its impact is significant and often underestimated. Here's how to think about vacancy and model it correctly in every deal.

What Is Vacancy Rate?

Vacancy rate is the percentage of potential rental income lost due to the property being unoccupied. It includes both physical vacancy (no tenant in place) and credit loss (tenant not paying).

Vacancy Loss = Gross Annual Rent × Vacancy Rate

On a property generating $24,000/year in gross rent, a 5% vacancy rate = $1,200 in lost income. At 10% vacancy, that doubles to $2,400.

What Vacancy Rate Should You Assume?

Never assume 0% vacancy, not even with a long-term tenant in place. Tenants move. Situations change. General guidelines:

5%: Tight rental market, well-located property, historically high occupancy. Minimum baseline.
7–8%: Standard assumption for most markets. Allows for 3–4 weeks vacancy per year.
10%+: Higher turnover market, older building, less desirable location, or higher-end units with fewer qualified applicants.

How Vacancy Cascades Through Your Numbers

Vacancy doesn't just reduce income. It has a cascade effect:

Lower effective gross income → lower NOI
Lower NOI → lower cap rate
Lower cap rate → lower implied property value
Lower cash flow → lower cash-on-cash return
Compounded over years → meaningfully lower IRR

In the Real-Estate Analyzer, you can run the stress test to simulate a vacancy spike, instantly seeing how doubling your vacancy rate changes every metric.

How to Minimize Vacancy

Price rent at or slightly below market to attract quality tenants quickly
Prioritize tenant screening. Longer tenancies mean less turnover
Maintain the property well. Tenants stay longer in well-maintained units
Give notice to prepare for re-letting before a tenant formally leaves
Consider offering a small rent incentive for 12–24 month lease renewals

Key Takeaways

1Never assume 0% vacancy. Use at least 5%, even for a fully-occupied property.
2Vacancy reduces income, NOI, cap rate, cash flow, and IRR. The effect cascades through every metric.
37–8% is a reasonable standard vacancy assumption for most single-family rental markets.
4Use the stress test feature to see exactly how a vacancy spike would affect your deal.

Ready to run these numbers on a real deal?

The Real-Estate Analyzer calculates every metric covered in this article—instantly, for free.

Analyze a deal for free

Back to all guides