Estimate Your Annual Property Tax in Alameda County, California

Estimate your Alameda County property tax for the 2026–27 tax year using your assessed property value, local tax rate, exemptions, and applicable charges. Enter your details below to get a quick annual and monthly estimate based on Alameda County’s current tax structure.

Alameda County Property Tax Calculator

Assessed value

City Or Representative Area

Custom TRA tax rate (%)

Homeowner exemption

Special assessments / fixed charges

Mello-Roos / CFD charges

Parcel taxes or local direct charges

Projected assessed value increase (%)

Estimated annual property tax

Taxable assessed value

Ad valorem tax

Direct charges

Monthly estimate

Two installment estimate

Projected next-year assessed value

Alameda CA Property Tax Due Dates 2026–27

Alameda County property taxes are generally paid in two installments. Use the dates below to plan your 2026–27 payments and avoid late penalties on your property tax bill.

First Installment

November 1, 2026 First installment of the 2026–27 secured property tax bill.

First Installment Delinquent

December 10, 2026 A 10% penalty applies after 5:00 p.m. if the first installment remains unpaid.

Second Installment

February 1, 2027 Second installment of the 2026–27 secured property tax bill.

Second Installment Delinquent

April 10, 2027 A 10% penalty plus a $10 cost applies after 5:00 p.m. if unpaid.

Important: December 10, 2026 and April 10, 2027 fall on weekdays, so the normal deadlines apply. The county notes that when a delinquent date falls on a weekend or legal holiday, payment by 5:00 p.m. on the next business day avoids the penalty.

Alameda County Property Tax Penalties

Missing an Alameda County property tax deadline can result in additional charges. Understanding when penalties apply can help you avoid unnecessary costs and keep your 2026–27 property tax payments on schedule.

What Happens If You Miss a Payment?

If the first installment is not paid by December 10, 2026, at 5:00 p.m., a 10% penalty is added to the unpaid installment. The second installment is due by April 10, 2027, at 5:00 p.m. If it remains unpaid, a 10% penalty plus a $10 cost may apply. These penalties can increase the total amount you owe, so paying before the deadlines is recommended.

Important Reminder for Property Owners

Mark December 10, 2026, and April 10, 2027, on your calendar as the key delinquency dates for the 2026–27 tax year. Paying each installment on time can help you avoid late-payment penalties and additional collection costs.

Explore More Alameda County Property Resources

Looking for more information beyond your tax estimate? Explore these helpful Alameda County resources to search properties, compare tax rates, calculate transfer costs, and understand local property records.

Property Search

Search Alameda County property records by owner, address, parcel number, and other available property details.

Tax Rates

Explore Alameda County property tax rates and understand how local rates can affect your estimated annual tax bill.

Document Stamp Calculator

Calculate estimated document stamp costs associated with transferring real estate property in Alameda County.

Property Guide

Find helpful information about property records, taxes, ownership, assessments, and other important Alameda County property topics.

How to Calculate Your Alameda County Property Tax

Use the calculator to estimate your Alameda County property tax by entering your property value, applicable tax rate, exemptions, local charges, and projected assessment increase. Follow these nine simple steps to get your estimated annual and monthly tax amounts.

Step 1

Enter your property's current assessed value. This amount is used as the starting point for calculating your estimated property tax.

Step 2

Choose your city or representative area from the dropdown to apply the corresponding Alameda County tax rate.

Step 3

If you know your property's exact TRA tax rate, enter it to replace the selected representative area rate.

Step 4

Enter the applicable homeowner exemption amount to reduce the assessed value used for your estimated tax calculation.

Step 5

Enter any special assessments or fixed charges that may apply directly to your property's annual tax bill.

Step 6

If your property has Mello-Roos or CFD charges, enter the applicable annual amount in the calculator.

Step 7

Add any parcel taxes or other local direct charges that may apply to your specific property.

Step 8

Enter your expected assessed value increase percentage to see an estimated value for the following year.

Step 9

Click Calculate Tax to view your estimated annual tax, taxable value, ad valorem tax, direct charges, monthly estimate, and installment amount.

Alameda County Property Tax Calculation Formula

Property Tax = 1% of Taxable Value + Voter-Approved Bond Debt + Applicable Special Assessments

For example: If your taxable value is $843,000, the 1% base property tax is $8,430. Additional voter-approved bond charges and special assessments can increase your final tax bill.

Visit Other California County Property Tax Calculators

Explore our separate property tax calculators for other California counties. Each calculator is designed to help you estimate local property taxes using county-specific rates, assessments, exemptions, and applicable charges.

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FAQ's

How is property tax determined in Alameda County?

Alameda County property tax is based on the taxable value assigned to a property and the applicable taxes and charges associated with that property.

What is the Proposition 13 property tax rule in Alameda County?

Proposition 13 generally limits the base property tax rate and restricts annual increases in assessed value, with reassessment rules applying when certain ownership or property changes occur.

How often is a property reassessed in Alameda County?

A property is generally reassessed when it changes ownership or undergoes qualifying new construction. Regular annual adjustments may also affect the assessed value under applicable California rules.

Does buying a home change its assessed value?

Yes. A change in ownership can trigger a reassessment based on the property’s new value, which may result in a different taxable assessment than the previous owner’s amount.

Can the assessed value be higher than the home's market value?

In some circumstances, the assessed value and current market value can differ significantly because California property assessments follow specific valuation and reassessment rules.

Where can I find my Alameda County property tax bill?

Property owners can access their tax bill and payment information through the Alameda County Treasurer-Tax Collector’s property tax services using the information associated with their parcel.

Can property taxes change after I purchase a property?

Yes. A purchase can trigger reassessment, and the resulting taxable value may differ from the previous assessment. Additional changes can also occur because of applicable local charges.

Are improvements to a property subject to reassessment?

Qualifying new construction or improvements can affect the assessed value of a property. The assessment generally applies to the value added by the qualifying improvement.

Can I appeal my Alameda County property assessment?

Property owners may have options to request a review or appeal an assessed value when they believe the assessment does not reflect the property’s appropriate taxable value under applicable assessment rules.

Why can two nearby Alameda County properties have different tax bills?

Two nearby properties can have different tax bills because their assessed values, ownership histories, exemptions, tax areas, special charges, and other property-specific factors may not be the same.