ADU RENT AND ROI
How much income could a San Diego ADU produce?
Enter a project cost, expected rent, vacancy, and operating costs. See what remains before loan payments.
THE SHORT ANSWER
Start with what the property earns.
Gross rent is not take-home income. Subtract vacancy and operating costs first. Then compare what remains with the loan payment and the cash you need to keep.
Check my propertyBEFORE THE CALCULATOR
Find a rent figure you can defend.
- Compare three to five similar listings near you. Current long-term listings with the same bedroom count and a similar size, detached or ground floor where you can find one, in your ZIP code. For each, write down the size, the features, the asking rent, the date and the link.
- Treat asking rents as asking rents. A listing that sat for two months and then dropped is evidence of the lower number; a signed lease is the only figure that is certain.
- Use a conservative range. Write down a low, a likely and a high from what you found. Enter the likely figure below, then try the low one. Keep the date you checked; rents move.
- Ask a property manager only if the evidence is thin. When you found fewer than three comparable listings, ask what a detached accessory unit rents for nearby, how long one usually sits empty between tenants, and what they would charge to manage it.
FREE ADU INCOME CALCULATOR
Try the numbers.
Change any number. The results update instantly.
These starting numbers are examples, not figures for your property. The result subtracts your vacancy allowance and the monthly operating costs you entered, and adds no other expenses on its own. Loan payments, income tax, changes in property value and sale value are not included.
Want to send someone the calculator on its own? Open the ADU income calculator — the same tool, on its own page.
COMMON QUESTIONS
What homeowners ask next.
What rent should I enter?
Use several recent long-term rental comparables that match the ADU's likely size, bedrooms, location, parking, utilities, and condition. Keep the range and source date.
What belongs in operating costs?
Include the recurring costs you expect to pay each month: utilities you cover, insurance, maintenance, management, and property tax on the new unit. The calculator subtracts only what you enter, so a cost you leave out is not counted anywhere.
Why does the calculator exclude financing?
Loan terms are household- and product-specific. This first screen isolates property operations; the $99 ADU Decision Kit compares financing scenarios on its own page.
Does a positive result mean I should build?
No. It means the assumptions produce a positive pre-debt operating result. The project, financing, risks, and household goals still need to be compared.
YOUR PROPERTY IS THE NEXT QUESTION
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