The Basic Formula: Assessed Value Times Tax Rate

California property tax starts with a single multiplication: the assessed value of your property times the tax rate set by your county. The assessed value is not what you paid for the house or what it might sell for today. It is the value the county assessor assigns to your property, and it follows a specific rule under Proposition 13.

The tax rate varies by county and by what local services your property funds — schools, fire, libraries, flood control. Most counties charge between 0.76% and 1.25% of assessed value, though the rate can be higher if your area has passed local bonds or special assessments. Your county assessor's office publishes the rate each year, and you can find it on their website or by calling them directly.

Key Takeaways

  • Your assessed value is locked at the price you paid when you bought the property, then increases by no more than 2% per year under Proposition 13, even if your home is worth much more.
  • The tax rate is a percentage set by your county and multiplied by your assessed value to produce your annual bill.
  • Your bill includes the base property tax plus any voter-approved bonds or special assessments that apply to your address.
  • You receive a bill in two installments each fiscal year, and the county assessor can show you the exact breakdown of what you owe and why.

How Assessed Value Works Under Proposition 13

When you buy property in California, the county assessor sets an assessed value equal to the purchase price. This is the foundation of your tax bill. The next year, that value can increase by up to 2%, and the year after that, another 2% — but no more. This cap continues every year you own the property, regardless of how much the real estate market rises around you.

If you bought your house for $400,000, the assessed value starts at $400,000. The following year it becomes $408,000 (2% increase). The year after, $416,160. Even if your neighborhood homes now sell for $600,000, your assessed value stays on that slow 2% climb until you sell or transfer the property. When you sell, the assessed value resets to the new sale price, and the 2% clock starts over.

Certain transfers do not trigger a reassessment — for example, passing property to a spouse or a child under age 18 in some cases. The county assessor's office maintains a list of these exceptions. If you think a transfer should have reset your assessed value and it did not, you can request a reassessment by filing a change-in-ownership form.

Tax Rate Breakdown and Local Assessments

The tax rate on your bill is not a single number. It is a stack of rates, each funding a different service. The base rate is set by state law at 1%, applied to your assessed value. On top of that sit rates for your county, your school district, your city (if you live in one), and any special districts that serve your address — such as a water district, fire protection district, or community college district.

When voters in your area pass a bond measure or a special tax, that rate gets added to your bill. A school bond might add 0.15% to your rate. A local infrastructure measure might add another 0.08%. These are not optional; if you own property in that district, you pay them. Your property tax bill will itemize each of these components so you can see which services your tax dollars fund.

To find your exact tax rate, contact your county assessor or visit their website. Most assessor offices have an online tool where you can enter your address and see the rate breakdown for your specific parcel. You can also call and ask for a breakdown by phone.

Reading Your Property Tax Bill

Your property tax bill arrives twice per year — usually in November and February — and covers two six-month periods. The bill shows your assessed value, the tax rate, the total amount due, and the due date. It also lists any penalties if you paid late in the past.

The bill may include supplemental taxes if your property was reassessed during the year — for example, because you built an addition or because you bought the property mid-year. A supplemental bill covers the difference between what you owed under the old assessed value and what you owe under the new one. These bills are prorated to the months remaining in the fiscal year.

If you do not understand a line item on your bill, the county assessor's office can explain it. You can also request a detailed assessment notice, which shows the assessed value, the date it was set, and the basis for it. This document is useful if you plan to appeal your assessment.

Appealing Your Assessed Value

If you believe your assessed value is too high, you can file a Proposition 8 appeal with your county assessor. This is a formal request to lower the assessed value based on evidence that the property is worth less than the county says it is. You have until the end of the fiscal year (usually June 30) to file, though some counties allow later filings if you have good cause.

To file an appeal, you submit a form to the assessor's office — available on their website — along with evidence supporting your claim. This might be a recent appraisal, comparable sales in your area, or documentation of damage or defects that reduce value. The assessor will review your evidence and either grant the appeal, deny it, or offer a compromise. If you disagree with their decision, you can appeal to the county Assessment Appeals Board.

Appeals are free to file, and you do not need a lawyer. However, if your property is worth significantly less than the assessed value and you have strong evidence, hiring an appraiser or a property tax consultant can strengthen your case. The cost of an appraisal typically ranges from $300 to $600, depending on the property.

Exemptions and Special Situations

Some properties are partially or fully exempt from property tax. Homeowners over age 65, disabled homeowners, and low-income homeowners may be may be able to access for a homeowner's exemption, which reduces the assessed value by a fixed amount (currently $7,000 in most counties, though this varies). You must file for this exemption with your county assessor; it does not happen automatically.

Agricultural land, open space, and certain nonprofit properties may also be exempt or taxed at a lower rate. If your property falls into one of these categories, contact your assessor to learn what exemptions you might claim and what documentation you need to provide.

If you receive a bill for property you no longer own, or if you believe you have been assessed twice for the same parcel, contact the assessor immediately. These errors do happen, and the assessor can correct them and issue a refund if you have overpaid.

Frequently Asked Questions

Why is my property tax bill so much higher than my neighbor's if our houses look the same?

The most common reason is that you bought your house more recently. Under Proposition 13, assessed value resets to the purchase price when you buy, then grows slowly. If your neighbor bought decades ago, their assessed value is much lower than yours, even though the houses are similar. The tax rate may also differ slightly if you live in different school districts or special assessment areas.

Can I pay my property tax in installments?

Yes. California property tax is billed in two installments per fiscal year. The first installment (July through December) is due by December 10, and the second (January through June) is due by April 10. You can pay each installment separately, or you can pay the full year's tax at once. If you pay late, penalties and interest accrue.

What happens if I do not pay my property tax?

If you do not pay by the due date, a penalty of 10% is added to the unpaid amount. After five years of nonpayment, the county can sell your property at a tax sale to recover the debt. You have a right to redeem the property (pay the debt plus costs) within a set period after the sale, but if you do not, you lose ownership. Contact your county tax collector if you are having trouble paying.

Does my property tax go down if my home value drops?

Not automatically. Your assessed value is capped at a 2% annual increase, so it does not rise with the market. But it also does not fall if the market drops — unless you file a Proposition 8 appeal and provide evidence that your property is worth less than the assessed value. The assessor will then review your evidence and decide whether to lower the value.

How do I find out what my assessed value is?

Your assessed value appears on your property tax bill. You can also look it up on your county assessor's website — most counties have a free online search tool where you enter your address or parcel number. You can also call the assessor's office and ask them to tell you the assessed value over the phone.