Cost and money
ADU cost and rental income calculator
Enter your own numbers: a contractor's bid, the city's fee estimate, your loan terms and the rent you expect. Everything runs in your browser; nothing is sent anywhere.
The numbers filled in are examples, not estimates for your project. Costs vary a lot by city, size and site. See what ADUs cost for figures from public studies, and your city's page for its fees.
Results
–Total project cost
–Monthly loan payment
–Monthly cash flow after the loanrent after vacancy, minus loan, tax and costs
–Years for rent to repay the costtotal cost ÷ yearly net rent (before the loan)
| Construction (size × cost per sq ft) | – |
|---|---|
| Soft costs, fees and site work | – |
| Contingency | – |
| Cost per square foot, all in | – |
| Yearly net rent before the loan | – |
| Return on total cost (yearly net rent ÷ cost) | – |
| Return on your cash (yearly cash flow ÷ cash in) | – |
| Rent needed to break even each month | – |
What the calculator leaves out
- Your home's value. An ADU may add to what your property is worth; an appraiser can tell you. This calculator only counts rent.
- Income tax. Rental income is taxable, and depreciation and expenses can offset it. Ask a tax professional.
- Loan details. It assumes one fixed-rate loan for everything you don't pay in cash. Construction loans, HELOCs and refinances work differently; see ways to pay for an ADU.
- Rent rules. Some cities limit short-term rentals of ADUs or require long rental terms. Check your city's page.
Related: what ADUs cost · how an ADU changes your property tax · garage conversions, usually the cheapest kind of ADU.