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Contra Costa County Property Tax Calculator

Contra Costa County's property tax bill traces back to the same Proposition 13 mechanics used statewide: the Contra Costa County Assessor's Office sets an assessed value at purchase, capped by state law to grow only modestly each year until a sale or major improvement resets it. As a commuter county within reach of both the East Bay and the Central Valley, home values here vary widely block to block, which makes the assessed-value baseline especially important to your actual bill. Above, set the calculator to Contra Costa County and fill in a home value for a projected total.

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Estimate Your California Property Tax
On a $866,800 home in Contra Costa County, your estimated annual property tax is $6,718 ($560/month) at an effective rate of 0.78%.
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02RESULTS

Annual Property Tax

$6,718

Monthly (Escrow)

$560

Effective Rate

0.78%

Contra Costa County's effective rate (0.78%) is 11% higher than the California average (0.70%).

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Contra Costa County Effective Rate

0.78%

Vs. California Average

11% higher

California National Rank

#32 of 51

1 = highest statewide rate

County Median Home Value

$866,800

Estimated Annual Tax (Median Home)

$6,718

Monthly Equivalent

$560

Property tax in Contra Costa County, California

  • The Contra Costa County Assessor's Office pins assessed value to the moment of purchase, and Proposition 13 caps its climb from there.
  • A change of ownership or a wrapped-up construction project both bring the figure current with the market.
  • The assessor's office offers a free review of a property's assessed value on request, ahead of any formal appeal to the county assessment appeals board.
  • Owner-occupants of a primary residence can apply for the homeowners' exemption, which trims taxable value in addition to the Proposition 13 cap.

Other large California counties

Effective rate = aggregate real-estate taxes paid ÷ aggregate home value (ACS 2024 5-year).

County Effective Rate Median Home Value
Los Angeles County 0.67% $834,200
San Diego County 0.67% $854,700
Orange County 0.64% $962,600
Riverside County 0.83% $557,300
San Bernardino County 0.73% $505,000
Santa Clara County 0.68% $1,490,600
Alameda County 0.76% $1,090,100
Sacramento County 0.76% $534,200
Kern County 0.89% $338,300
Imperial County 0.83% $309,600

See property tax across every county in California at the California property tax calculator , or check your California income tax with the California income tax calculator .

Frequently asked questions

How is property tax calculated in Contra Costa County?

The Contra Costa County Assessor's Office pins your figure to Proposition 13's rules at the time of purchase, and the rate area covering your parcel bills against that number instead of what the home would fetch today. Because the cap only resets at sale or major improvement, how long you've owned the home matters as much as its location.

How do I appeal my Contra Costa County assessment?

You can request a free informal review of your assessed value directly from the assessor's office, and if you still disagree, the county's appeals board takes formal filings ahead of the annual deadline.

Does Contra Costa County offer a homestead exemption?

Yes — an owner-occupied home in Contra Costa gets California's homeowners' exemption, trimming the taxable figure beyond whatever Proposition 13 has already capped.

Why does my Contra Costa County neighbor pay less property tax than me?

Most likely because they've owned their home longer and their assessed value has only grown by Proposition 13's capped annual amount, while your assessed value reset to a higher purchase price when you bought more recently. Local levy rates within the same tax rate area are typically similar, so the gap usually comes down to assessed value.

Sources

Related insights

Use these guides for rule explanations, planning context, and follow-up questions beyond the calculator result.

Related Calculators

Last updated July 24, 2026 Tax year 2026 property tax estimates

Data sources: U.S. Census Bureau ACS 2024 5-year ACS + Tax Foundation

This tool is general information only, not financial advice.

Estimates are aggregate-derived from Census ACS data; actual bills depend on city, school-district, and special-district levies layered on top of the county rate, and on any homestead, senior, veteran, or other exemptions you qualify for.

Reviewed by USTax Tools Editorial Desk

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