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Tax year 2026

San Mateo County Property Tax Calculator (2026)

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The San Mateo County median effective property tax rate is 0.63% for 2026 (U.S. Census Bureau ACS 2024), 0.07% below the California median of 0.7%. On a $400,000 home that is about $2,520 a year (~$210 a month). San Mateo County property is assessed by the San Mateo County Assessor-County Clerk-Recorder. Enter your home value below for an instant estimate.

What is the San Mateo County property tax rate in 2026?

San Mateo County's median effective property tax rate is 0.63% (U.S. Census Bureau ACS 2024). The county median home is $1,559,600 with a median tax of about $9,519.

How much is property tax on a $400,000 home in San Mateo County?

About $2,520 a year, or roughly $210 a month, at the 0.63% median effective rate before exemptions.

Who handles property tax in San Mateo County?

The San Mateo County Assessor-County Clerk-Recorder sets your assessed value. The San Mateo County Tax Collector collects the bill. Appeal by File a regular assessment appeal between July 2 and November 30.

When are San Mateo County property taxes due?

Two installments: the first is due November 1 (delinquent after December 10) and the second is due February 1 (delinquent after April 10).

San Mateo County Property Tax Calculator (2026)

Rates updated 2026 (U.S. Census Bureau ACS 2024). Live estimate — county median effective rate.

Home value$1,559,600
Estimated annual property tax$9,825
Estimated monthly (escrow)$819
San Mateo County effective rate0.63%
California median: 0.7%US avg: 0.94%

San Mateo County's median effective property tax rate is 0.07% below the California median and the US average is 0.94%. Your assessed value, local millage, and exemptions (homestead, senior, veteran) will change the actual bill.

Who assesses and collects property tax in San Mateo County?

In San Mateo County, the San Mateo County Assessor-County Clerk-Recorder sets the assessed value of your home each year. The San Mateo County Tax Collector issues the bill and collects payment. Assessment appeals are heard by the San Mateo County Assessment Appeals Board.

For your exact rate, exemptions, and account details, go to smcacre.gov — the official source for San Mateo County. This page is an independent estimate, not a tax bill.

How much is property tax on a home in San Mateo County?

At the San Mateo County median effective rate of 0.63%, here is the estimated annual and monthly bill by home value. The county median home value is $1,559,600, with a median tax of about $9,519 a year.

Home valueRate (0.63%)Annual taxMonthly
$200,0000.63%$1,260$105
$400,0000.63%$2,520$210
$1,559,600 (county median)0.63%$9,519$793
$750,0000.63%$4,725$394

When are San Mateo County property taxes due, and when can you appeal?

Assessment (lien) date: January 1 (lien date); reassessed on a change of ownership or new construction under Proposition 13. Proposition 13 — assessed value is the purchase price plus up to 2% inflation per year, reset only on sale or new construction.

Payment: Two installments: the first is due November 1 (delinquent after December 10) and the second is due February 1 (delinquent after April 10).

Appeal window: File a regular assessment appeal between July 2 and November 30. Missing it usually means accepting the assessed value for the year.

What exemptions can lower your San Mateo County property tax?

ExemptionAmount or rule
Homeowners' Exemption$7,000 off assessed value (about $70/year); file by February 15 for the full amount, late claims get $5,600
Disabled Veterans' Exemptionexempts a large share of assessed value for qualifying disabled veterans and surviving spouses
Proposition 19 base-value transferowners 55+, disabled, or wildfire/disaster victims can move their Prop 13 base value to a replacement home

Amounts and eligibility change over time and are administered locally, so confirm what you qualify for with the San Mateo County Assessor-County Clerk-Recorder before relying on a figure.

How do you estimate your San Mateo County property tax by hand?

  1. Find your home's assessed value on your latest notice from the San Mateo County Assessor-County Clerk-Recorder.
  2. Subtract any exemptions you qualify for, such as homestead, senior, or veteran relief.
  3. Multiply the remaining taxable value by your local combined tax rate.
  4. For a quick estimate, multiply your home value by 0.63% — the San Mateo County median effective rate used above.

Which cities are in San Mateo County, and what makes it different?

San Mateo County includes San Mateo, Redwood City, Daly City, South San Francisco, San Bruno, Menlo Park, Foster City, Burlingame, Belmont, among others. Rates differ between these cities and their school and special districts, so two homes of equal value can owe different amounts.

San Mateo County (the Peninsula) has some of the highest home values in the country, so even a sub-1% effective rate produces large dollar bills — the Census median tax is top-coded. Proposition 13 ties your bill to your purchase price, not the current market, and the regular appeal window runs through November 30.

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Verified by our data team

Last updated: June 22, 2026. San Mateo County's effective rate is from the U.S. Census Bureau ACS 2024; the assessor, payment due dates, appeal deadline and exemptions were confirmed against the San Mateo County Assessor-County Clerk-Recorder and the San Mateo County Tax Collector on June 22, 2026.

What are the most frequently asked questions?

  • San Mateo County's median effective property tax rate is 0.63% (median tax paid divided by median home value, U.S. Census Bureau ACS 2024). Your exact rate is set by local districts and the San Mateo County Assessor-County Clerk-Recorder.

  • About $1,890 a year, or roughly $158 a month, at the 0.63% median effective rate before exemptions.

  • File a regular assessment appeal between July 2 and November 30. File with the San Mateo County Assessment Appeals Board.

  • Two installments: the first is due November 1 (delinquent after December 10) and the second is due February 1 (delinquent after April 10).

  • San Mateo County offers Homeowners' Exemption, Disabled Veterans' Exemption, Proposition 19 base-value transfer. Amounts vary and are administered locally — confirm eligibility with the San Mateo County Assessor-County Clerk-Recorder.

  • San Mateo County's 0.63% effective rate is 0.07% below the California median of 0.7% and 0.31% below the 0.94% US average.

Disclaimer: this page is for educational and estimation purposes only; it is property-tax research, NOT tax or legal advice. Property tax in San Mateo County is assessed locally by the San Mateo County Assessor-County Clerk-Recorder and the cities, school districts and special districts within the county. Figures use the county median effective rate (U.S. Census Bureau ACS 2024); your assessed value, local millage and exemptions will change the actual bill. Always confirm with the San Mateo County Assessor-County Clerk-Recorder or a qualified professional.