California Property Tax Calculator

What is Proposition 13?

Passed in 1978, Prop 13 limits California property tax to 1% of the assessed value (purchase price or fair market value at purchase) plus local voter-approved taxes. Annual assessment increases are capped at 2% per year — far below actual home price appreciation. This means long-time California homeowners pay far less tax than new buyers on equivalent properties.

Does my property tax reset when I sell?

Yes — when a property sells, the assessed value resets to the new purchase price. This is why long-time California homeowners face a "lock-in effect" — selling means giving up a low assessed value and triggering a much higher tax on the new owner. Proposition 19 (passed 2020) allows transfers between parents/children to retain Prop 13 basis under certain conditions.

When is California property tax due?

California property taxes are paid in two installments: first half (July 1–Dec 31) is due Nov 1, delinquent Dec 10; second half (Jan 1–June 30) is due Feb 1, delinquent April 10. Many homeowners pay through their mortgage escrow, which the lender manages automatically.

What is a supplemental property tax?

When you buy a California property, you receive a supplemental tax bill for the difference between your new assessed value and the prior owner's assessed value — prorated for the portion of the year you owned it. This can be a surprise payment of several thousand dollars in the first year. Budget for it when purchasing.