King County property tax calculator 2026
This calculator provides an estimated property tax for real estate located in King County, Washington. The estimate is based on assessed value and a combined local property tax levy rate that varies by levy code area.
Estimates only. Loan terms and approval depend on lender underwriting.
Many U.S. counties use multiple local taxing authorities (county, city, school district, special districts). Enter your combined local millage rate as shown on your annual property tax notice.
Estimated property tax
Enter the assessed value to see the estimated annual property tax.
How it works
Property tax in King County is calculated using the assessed value determined by the King County Assessor. Multiple taxing districts—such as the county, cities, school districts, and other special districts—adopt levies that are combined into a single levy rate for each levy code area. The assessed value is multiplied by this combined levy rate (expressed per $1,000 of assessed value) to estimate annual property tax.
Examples
Two properties with the same assessed value can have different estimated taxes if they are located in different levy code areas within King County. Different combinations of taxing districts and voter-approved levies result in different combined rates.
Limitations and important notes
This estimator provides a simplified calculation based on the value and rate entered. King County does not have a single uniform property tax rate. Combined levy rates vary by levy code area and by year, and voter-approved excess levies or special assessments may apply. Exemptions, credits, and parcel-specific adjustments are not deterministically modeled. Actual tax bills may differ from this estimate.
FAQs
How is property tax calculated in King County, Washington?
The estimate is based on assessed value multiplied by a combined local levy rate that applies to the property’s levy code area.
What value should I enter into the calculator?
Enter the property’s assessed value as determined by the King County Assessor.
Why do property tax rates vary within King County?
Rates vary because each levy code area includes a different combination of taxing districts and voter-approved levies.
Are exemptions or credits included in this estimate?
No. Exemptions, credits, and parcel-specific adjustments are not included and can change the final tax bill.
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Calculations are simplified and for guidance only. Always double-check results and current rules with official sources or a qualified professional before making financial decisions.