King County Property Tax Calculator (2026)
The King County median effective property tax rate is 0.76% for 2026 (U.S. Census Bureau ACS 2024), 0.05% below the Washington median of 0.81%. On a $400,000 home that is about $3,040 a year (~$253 a month). King County property is assessed by the King County Assessor. Enter your home value below for an instant estimate.
What is the King County property tax rate in 2026?
King County's median effective property tax rate is 0.76% (U.S. Census Bureau ACS 2024). The county median home is $859,900 with a median tax of about $7,114.
How much is property tax on a $400,000 home in King County?
About $3,040 a year, or roughly $253 a month, at the 0.76% median effective rate before exemptions.
Who handles property tax in King County?
The King County Assessor sets your assessed value. The King County Treasury collects the bill. Appeal by File with the King County Board of Equalization by July 1.
When are King County property taxes due?
Two halves: the first is due April 30 and the second is due October 31.
King County Property Tax Calculator (2026)
Rates updated 2026 (U.S. Census Bureau ACS 2024). Live estimate — county median effective rate.
King County's median effective property tax rate is 0.05% below the Washington median and the US average is 0.94%. Your assessed value, local millage, and exemptions (homestead, senior, veteran) will change the actual bill.
Who assesses and collects property tax in King County?
In King County, the King County Assessor sets the assessed value of your home each year. The King County Treasury issues the bill and collects payment.
For your exact rate, exemptions, and account details, go to kingcounty.gov — the official source for King County. This page is an independent estimate, not a tax bill.
How much is property tax on a home in King County?
At the King County median effective rate of 0.76%, here is the estimated annual and monthly bill by home value. The county median home value is $859,900, with a median tax of about $7,114 a year.
| Home value | Rate (0.76%) | Annual tax | Monthly |
|---|---|---|---|
| $200,000 | 0.76% | $1,520 | $127 |
| $400,000 | 0.76% | $3,040 | $253 |
| $859,900 (county median) | 0.76% | $7,114 | $593 |
| $750,000 | 0.76% | $5,700 | $475 |
When are King County property taxes due, and when can you appeal?
Assessment (lien) date: January 1. Annual — the Assessor revalues property every year, while Washington caps each regular levy's growth at 1% per year.
Payment: Two halves: the first is due April 30 and the second is due October 31.
Appeal window: File with the King County Board of Equalization by July 1, or within 60 days of the date your valuation notice was mailed, whichever is later. Missing it usually means accepting the assessed value for the year.
What exemptions can lower your King County property tax?
| Exemption | Amount or rule |
|---|---|
| Senior & disabled exemption | freezes the taxable value and exempts some levies for owners 61+ or disabled who meet income limits |
| Senior & disabled deferral | lets qualifying owners defer payment; the first half (due April 30) must be paid before deferring the second |
| Disabled veteran relief | income-based exemption for veterans with a service-connected disability |
Amounts and eligibility change over time and are administered locally, so confirm what you qualify for with the King County Assessor before relying on a figure.
How do you estimate your King County property tax by hand?
- Find your home's assessed value on your latest notice from the King County Assessor.
- Subtract any exemptions you qualify for, such as homestead, senior, or veteran relief.
- Multiply the remaining taxable value by your local combined tax rate.
- For a quick estimate, multiply your home value by 0.76% — the King County median effective rate used above.
Which cities are in King County, and what makes it different?
King County includes Seattle, Bellevue, Kent, Renton, Federal Way, Kirkland, Auburn, Redmond, Sammamish, Shoreline, among others. Rates differ between these cities and their school and special districts, so two homes of equal value can owe different amounts.
King County (Seattle) has no state income tax and revalues every year, but Washington caps each regular property-tax levy's growth at 1% a year, so most increases come from new voter-approved levies. There is no general homestead exemption; relief is targeted at seniors, people with disabilities, and disabled veterans.