The direct answer
A self-storage investment scenario follows occupied unit revenue and ancillary income into NOI, then compares property-level yield and after-debt cash return. Unit count, occupancy and average rent simplify a facility with potentially different unit sizes and collection patterns.
Build the capacity-income bridge
Multiply total units by average occupancy, average monthly rent and 12, then add ancillary income. Fractional average occupied units are acceptable in an annual planning model, even though the physical unit count is whole. The same average rent for every occupied unit can hide unit-mix differences, discounts and collections. Review the evidence behind that average before drawing conclusions.
To apply the approach to an editable scenario, use the Self-Storage Investment Calculator. For the neighboring question, explore Self-Storage Valuation Calculator.
Reconcile operating and financing assumptions
Deduct annual operating expenses for NOI, then annual debt service for cash flow. Management, utilities or other relevant obligations should be in the supplied operating budget if applicable. The tool does not derive costs from facility size, retrieve storage rents or calculate financing. Capital replacements and unentered transaction costs need separate consideration.
Keep total investment and cash invested distinct
The model divides NOI by total investment for its property-level yield. Cash-on-cash divides after-debt cash flow by contributed cash. Financing can make those bases different. Compare the annual dollar cash result with liquidity needs and test occupancy or rate changes, rather than judging the facility only by a headline percentage.
Worked example
Two hundred units at 90% average occupancy and $120 monthly rent produce $259,200 annual unit revenue. Adding $20,000 ancillary income gives $279,200. Less $100,000 operating costs gives $179,200 NOI; less $80,000 debt service leaves $99,200 cash flow. On $500,000 cash invested, cash-on-cash is 19.84%.
Open Self-Storage Investment Calculator and test your assumptions →
Common mistakes and limitations
Do not confuse physical occupancy with retained revenue when unit rents differ. Do not divide after-debt flow by total facility cost and label it the same as equity cash-on-cash.
Does not model unit-size mix, dynamic pricing, delinquency or capex unless user includes them.
Frequently asked questions
Why can average occupied units be fractional?
It represents occupancy across the year, rather than a snapshot physical count.
Does the tool supply a market rent?
No. The average monthly unit rent is an editable user assumption.
Sources and further reading
The article’s examples are illustrative arithmetic. The references below provide context for operating, valuation or transaction concepts; they do not endorse the assumptions or the calculator.
- Office of the Comptroller of the Currency — Comptroller's Handbook — Commercial Real Estate LendingNOI, direct capitalization, cap-rate valuation and DCF concepts for commercial real estate.
Read our editorial policy for the scope of these educational methods.