How does a California landlord calculate a legal rent increase?
Step 1: confirm the unit is covered (most are, but Single-family homes or condos owned by a natural person (or LLC whose members are all natural persons post-AB 414), with written notice to tenant and Buildings with certificate of occupancy issued within the last 15 years (rolling exemption) may be exempt). Step 2: calculate the cap: lower of 5% + CPI or 10% flat. Step 3: multiply current rent by the cap to get the maximum dollar increase. Step 4: serve the proper advance notice (Cal. Civ. Code 827(b)). Step 5: the new rent takes effect on the notice's effective date, no earlier.
Source: Cal. Civ. Code 827(b)
This is an informational answer based on Cal. Civ. Code 827(b) as of early 2026. It is not legal advice. Housing law changes year to year and local ordinances (especially in rent-controlled or rent-stabilized cities) can override or add to state law. For contested cases, consult a California-licensed attorney.