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Portola Valley, San Mateo County, California Property Taxes

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Property Taxes in Portola Valley, California

  • Median Portola Valley, California effective property tax rate: 1.10%, significantly lower than the national median of 1.02%, and lower than the California state median of 1.21%.

  • Median Portola Valley, California home value: $2,320,354

  • Median annual Portola Valley, California tax bill: $24,816, higher than the national median property tax bill of $2,400.

How are property taxes in San Mateo calculated?

Property taxes in Portola Valley, California are calculated based on the tax assessed value, which is often lower than the actual market value due to property tax exemptions such as the homestead or senior exemption.

Understanding Portola Valley's property tax system, exemptions, and reduction opportunities can lead to significant savings. Regardless of where you live in Portola Valley, knowing local tax details benefits homeowners and investors.

Last Updated April 13, 2026

Portola Valley, San Mateo County, California Property Tax Bill Calculator

$100,000

$1,500,000

$3,000,000

Median Effective Tax Rate

1.1%

Estimate Property Tax Bill

$25,524

$23,685

SAVE WITH OWNWELL

$774

Average Annual Tax Savings

How Does the Portola Valley Property Tax Calculator Work?

Use this Portola Valley property tax calculator to estimate your annual tax bill. Enter your property's assessed value and our calculator applies Portola Valley's median effective tax rate of 1.10% — based on actual property records in San Mateo County — to generate your estimate.

Enter your property's estimated assessed value — the figure the local assessment system uses to calculate your bill, which reflects any exemptions you hold and is typically lower than your home's market value. Our calculator applies Portola Valley's median effective rate across all local levies, providing a more accurate estimate than applying a single county millage rate.

Your bill may vary by ZIP code within Portola Valley: rates range from 1.10% in 94028 to 1.10% in 94028, primarily due to differences in school district levies and local assessment districts. Portola Valley's median tax bill of $24,816 is higher than the national median property tax bill of $2,400 and higher than the national median property tax rate of 1.02%.

If your estimate is higher than expected, Ownwell can appeal your Portola Valley assessment — you only pay if we save you money.

About Portola Valley Property Taxes

About Property Taxes in Portola Valley, San Mateo, California

Portola Valley’s median effective property tax rate of 1.10% is lower than the California state median of 1.21% and higher than the national median of 1.02%. This rate reflects the San Mateo County base levy combined with local school district levies and Mello-Roos Community Facility Districts that vary by subdivision throughout the city.

Property tax rates are not uniform across Portola Valley. Homeowners in the 94028 ZIP code carry a median effective rate of 1.10%, while those in the same ZIP code pay 1.10%. This spread reflects how school district boundaries and local assessment districts are drawn across San Mateo County. Understanding which part of Portola Valley you live in can make a meaningful difference to your annual tax bill.

Portola Valley homeowners who believe their assessed value is too high can file a formal appeal with the local Tax Assessor before the December 1, 2026 deadline each year.

If your estimated bill above seems higher than expected, Ownwell can review your assessment and protest on your behalf. You only pay if we save you money.

Property Tax Rates Across Portola Valley, San Mateo County, California

As noted earlier, local government entities set tax rates, which can vary widely within a state.

Why? Because annually, each county estimates its required budget to provide services and divides that by the total value of all taxable property within its jurisdiction. This calculation results in the property tax rate.

While there are votes and laws involved in setting tax rates and budgets, in a nutshell, this is the annual process.

Below, you can compare Portola Valley's effective property tax rate to other cities in California and the median property tax rates in California and the U.S.

Property Tax Rates Across Portola Valley, San Mateo County, California

Source: Ownwell

1.07%

1.27%

1.47%

Our median effective property tax rate (tax bill ÷ assessor's market value) accounts for exemptions and deductions, making it more accurate than the general median tax rate, which is the midpoint of statutory rates before adjustments.

Median Effective Portola Valley Tax Rate

1.10%

Our median effective property tax rate (tax bill ÷ assessor's market value) accounts for exemptions and deductions, making it more accurate than the general median tax rate, which is the midpoint of statutory rates before adjustments.

Median Effective San Mateo County Tax Rate

1.23%

Median Effective California Tax Rate

1.21%

Median Effective United States Tax Rate

1.02%

Property Tax Rates Across Portola Valley, San Mateo County, California

Zip10th Percentile25th PercentileMedian Tax Rate75th Percentile90th Percentile
940281.05%1.07%1.10%1.15%1.31%

Source: Ownwell

Property Tax Assessment Values Across Portola Valley, San Mateo County, California

When examining property taxes in Portola Valley, California, understanding the distinction between "market value" and "assessed value" is crucial.

The market value is what a willing buyer would pay to a willing seller in an open and competitive market, often influenced by location, property condition, and economic market trends. The San Mateo County assessment office estimates the market value for tax purposes.

The assessed value is the market value minus any applicable exemptions or limits determined by local laws and offerings. The tax assessed value is the figure used to calculate your property taxes or the amount multiplied by your tax rate to get your tax bill.

Assessment notices:

In San Mateo County, assessment notices are sent in the spring each year. They'll typically reach your mailbox by the middle of October.

Each property owner receives an assessment notice that contains both the market value and assessed value, along with an estimate of your property tax bill. For Portola Valley, the median home price is $2,320,354, with a median tax bill of $24,816. Tax bills range from $12,518 at the 25th percentile to $58,623 at the 90th percentile, showing how property taxes can vary across the county.

Property Tax Assessment Values Across Portola Valley, San Mateo County, California

Source: Ownwell

$462,344

$2,599,052

$4,735,760

Median Portola Valley Market Value

$2,320,354

Median San Mateo County Market Value

$810,000

Median California Market Value

$427,605

Median United States Market Value

$235,294

Property Tax Assessment Values Across Portola Valley, San Mateo County, California

Zip10th Percentile25th PercentileMedian Home Price75th Percentile90th Percentile
94028$370,189$1,132,292$2,320,354$3,724,372$5,559,579

Source: Ownwell

Property Tax Bills Across Portola Valley, San Mateo County, California

Property tax bills in Portola Valley are calculated by applying the local tax rate to a home’s assessed value, which is based on the market value of the property. For homeowners in San Mateo County, the median home price is $2,320,354, and that value helps shape what many residents owe each year. The 25th percentile tax bill is $12,518, while the 75th percentile is $39,080 and the 90th percentile is $58,623, showing how quickly property taxes can rise for higher-value homes. Compared with the national median property tax rate of 1.02% and the national median property tax bill of $2,400, Portola Valley homeowners often face much larger bills. These taxes can significantly affect household budgets, especially when assessments climb faster than expected. Ownwell helps homeowners save by reviewing assessments, identifying opportunities for a property tax appeal, and pursuing exemptions when available so you do not pay more than you should.

Property Tax Bills Across Portola Valley, San Mateo County, California

Source: Ownwell

$4,835

$26,810

$48,785

Median Portola Valley Tax Bill

$24,816

Median San Mateo County Tax Bill

$9,758

Median California Tax Bill

$5,134

Median United States Tax Bill

$2,400

Property Tax Bills Across Portola Valley, San Mateo County, California

Zip10th Percentile25th PercentileMedian Tax Bill75th Percentile90th Percentile
94028$4,426$12,518$24,816$39,080$58,623

Source: Ownwell

Don't miss the deadline to appeal!

Frequently Asked Property Tax Questions in Portola Valley, California

How are property taxes calculated in Portola Valley, California?
Property taxes in Portola Valley, California are calculated by multiplying your property's assessed value by the applicable tax rate set by local taxing authorities. The assessed value is determined by the county assessor and may differ from your property's market value depending on local assessment ratios and exemptions.
How do I appeal my property taxes in Portola Valley, California?
To appeal your property taxes in Portola Valley, California, you typically need to file a formal protest or appeal with your local appraisal district or assessor's office by the stated deadline. You'll need evidence such as comparable sales, a recent independent appraisal, or documentation of property condition issues. Ownwell can handle this entire process for you.
What property tax exemptions are available in Portola Valley, California?
Common property tax exemptions in Portola Valley, California include homestead exemptions for primary residences, senior citizen exemptions, veteran exemptions, and disability exemptions. Exemption amounts and eligibility requirements vary by county. Contact your local appraisal district or check Ownwell for details specific to your property.
When are property taxes due in Portola Valley, California?
Property tax deadlines in Portola Valley, California vary by county but typically include an assessment notice period in spring or early summer, followed by an appeal deadline, and a tax payment due date in the fall or winter. Check with your county assessor's office for specific dates in your area.
How can Ownwell help reduce my property taxes in Portola Valley, California?
Ownwell provides professional property tax appeal services in Portola Valley, California. Our team analyzes your assessment, gathers evidence, files all paperwork, and represents you at hearings — all with no upfront cost. You only pay a percentage of your savings if we successfully lower your tax bill.