Sonoma County property tax calculator 2026

How it works

In Sonoma County, property tax is based on assessed value under California law. Real property is generally reassessed to market value when ownership changes or new construction is completed, establishing a new base-year value. Annual increases to the factored base-year value are generally limited to no more than 2% per year. The taxable value is typically the lower of current market value or the factored base-year value. The statewide base rate is 1% of taxable value, and additional voter-approved rates may apply depending on the property’s tax-rate area.

Examples

When a property in Sonoma County is reassessed following a transfer or new construction, a supplemental tax bill may be generated in addition to the regular annual levy. For example, if the updated assessed value becomes 720,000 mid-year, the additional tax is calculated separately from the secured roll billing cycle. The estimator reflects the primary annual roll value rather than interim adjustments.

Limitations and important notes

This calculator provides an estimated property tax only. In Sonoma County, total rates vary by tax-rate area because voter-approved bonds and special assessments differ across geographic areas. Disabled veteran exemption amounts are adjusted for inflation and vary by eligibility and year. Your actual tax bill may differ based on your specific tax-rate area, exemptions, and assessment history.

FAQs