Honest ADU numbers, first.
AduCalc is a transparent California ADU cost, rent, and feasibility calculator built for homeowners. We believe you should see real numbers — with the assumptions behind them — before you talk to a builder, refinance, or make an offer.
What we do
We turn your city, ADU type, size, finish, and goal into a transparent cost range, monthly rent estimate, gross yield, and net payback. Every number is a range, never a false-precision guess, and we show you the multipliers behind it.
No spam. No lead flipping.
- We don't sell or syndicate your information to contractors.
- We don't give legal or zoning advice — only directional guidance.
- We don't pretend a calculator replaces a site visit, a contractor bid, or a permit-ready plan.
How we tune the numbers
Our cost and rent assumptions are calibrated against 2024–2026 California ADU project data, the California HCD ADU Handbook, and public rent benchmarks. We update them when the market shifts — and we flag low-confidence estimates when we can't match your city or ZIP to a known market.
See the numbers for your property.
Five questions. A transparent ADU estimate, built for California homeowners.