Rental Vacancy Rate Calculator

Rental vacancy rate calculator measures unrented property %. 5 vacant of 100 units = 5% vacancy. Critical metric for cash flow planning. Each 1% vacancy = 1% revenue loss before any other expenses. Strong markets: under 5% vacancy. Weak markets: 10-15%+ vacancy. National average: 7-8% private rental vacancy.

Example: 100-unit apartment building. 95 occupied, 5 vacant. Vacancy rate = 5%. Healthy. Annual gross potential rent 1.8M. Vacancy loss = 90,000. After other expenses, this 90k could be the difference between profit and loss. Tight markets allow rent increases; loose markets force concessions (free month, deposit waiver).

Vacancy benchmarks by area: Zone 1: 2-4% (very tight). Zone 4-6: 5-7%. Regional cities: 6-9%. Northern industrial: 8-12%. Student towns (academic year): 0% term-time, 30%+ summer. Track local vacancy rate via council/agent reports. Pricing decisions depend heavily on market vacancy - 3% vacancy lets you push rents 3-5% annually; 12% vacancy means accepting current rents to maintain occupancy.

Quick example

With vacant units of 5 and total units of 100 (plus or: vacancy days of 0 and or: total rental days of 0), the result is 5.00%. Change any figure and watch the output shift — it's often more useful to see the pattern than to memorise the formula.

Which inputs matter most

You enter Vacant Units, Total Units, OR: Vacancy Days, and OR: Total Rental Days. Not every input has equal weight. Adjusting one input at a time toward extreme values shows which ones move the result most.

What's happening under the hood

Unit-based: vacant / total. Time-based: vacancy days / total possible days. The formula is listed in full below. If the number looks off, you can retrace the calculation by hand — that's the point of showing the working.

Where this fits in planning

This is a "what-if" tool, not a forecast. Use it to test ideas before committing: what happens if the rate is 2% lower than hoped, what happens if you add five more years. The value is in the scenarios you run, not the single answer you get from the defaults.

What this doesn't capture

Steady-rate math ignores real-world volatility. Actual returns are lumpy; sequence-of-returns risk matters most in drawdown; fees and taxes drag on compound growth; and behaviour changes in drawdowns can reduce outcomes below the projection. The number represents one scenario rather than a forecast.