What King County property tax looks like
Among the 30 counties covered here, King County has the 19th highest effective rate and the 3rd highest median bill. Every $100,000 of value carries about $836 of tax a year at this rate.
On a $400,000 purchase that comes to roughly $3,344 a year, or $279 a month. Priced at the Washington average rate instead, the same home would cost $1 a month more in tax.
The Assessor revalues every property each year, and bills are paid in two halves, due April 30 and October 31. Washington limits how fast each taxing district's regular levy can grow, so rates tend to fall when values jump.
Parcel-level values and tax history are published by the King County Department of Assessments.
Example monthly payment at the median home value
Borrowing $648,960 against a $811,200 King County home (20% down, 6.5% for 30 years, illustrative rather than quoted) works out as follows.
| Component | Per month |
|---|---|
| Principal and interest | $4,102 |
| Property tax | $565 |
| Homeowners insurance | $150 |
| Mortgage insurance (PMI) | $0 |
| Total | $4,817 |
Property tax is 11.7% of the $4,817 total, so a lender escrowing it would set aside about $565 each month toward the King County bill.
How reliable this figure is
For King County the Census Bureau reports a 90% margin of error of ±$38 on the $6,785 median tax and ±$5,949 on the $811,200 median value, so the 0.836% rate is a county-wide average rather than the rate on any one bill.
These medians describe today's owners, not today's buyers. How Washington values and caps a home, including what resets on sale, is set out on the Washington page.
Counties with a similar rate
Frequently asked questions
What is the property tax rate in King County, WA?
The effective rate is 0.836%, which is the median real estate tax paid ($6,785) divided by the median home value ($811,200) in the Census Bureau's 2019-2023 estimates.
How much is property tax on a $400,000 home in King County?
At this county's effective rate the figure is about $3,344 a year, or $279 a month. That is $1 a month less than the Washington average rate of 0.84% would give on the same price.
How much of a King County monthly mortgage payment is property tax?
On a $811,200 home with 20% down at 6.5% over 30 years, property tax is about $565 of a $4,817 total monthly payment, or 11.7%.
Is property tax in King County high compared with the rest of Washington?
King County's 0.836% is 0.00 percentage points below the 0.84% Washington average, and its $6,785 median bill ranks 3rd of the 30 counties covered here, with the rate ranking 19th.
Source and method
Census American Community Survey, ACS 2019-2023 5-year estimates, released December 2024. For King County: B25103 median tax $6,785, B25077 median value $811,200, B25003 520,391 owner-occupied homes. Formulas are on the methodology page; every result is an estimate, not a quote or tax advice.