Property Taxes in Castle Rock, Washington
Median Castle Rock, Washington effective property tax rate: 0.80%, significantly lower than the national median of 1.02%, and lower than the Washington state median of 0.92%.
Median Castle Rock, Washington home value: $369,030
Median annual Castle Rock, Washington tax bill: $2,929, $529 higher than the national median property tax bill of $2,400.
How are property taxes in Cowlitz calculated?
Property taxes in Castle Rock, Washington are calculated based on the tax assessed value, which is often lower than the actual market value due to property tax exemptions such as the homestead or senior exemption.
Understanding Castle Rock's property tax system, exemptions, and reduction opportunities can lead to significant savings. Regardless of where you live in Castle Rock, knowing local tax details benefits homeowners and investors.
Last Updated April 13, 2026
How Does the Castle Rock Property Tax Calculator Work?
Use this Castle Rock property tax calculator to estimate your annual property tax bill. Enter your property's assessed value and our calculator applies Castle Rock's median effective tax rate of 0.80% — based on actual property records in Cowlitz County — to generate your estimate.
Enter your property's estimated assessed value — the figure the local appraisal district uses to calculate your bill, which reflects any exemptions you hold and is typically lower than your home's market value. Our calculator applies Castle Rock's median effective rate across all local levies, providing a more accurate estimate than applying a single county millage rate.
Your bill may vary by ZIP code within Castle Rock: rates range from 0.80% in 98611 to 0.80% in 98611, primarily due to differences in school district levies and local assessment districts.
For a more precise estimate, scroll down to explore ZIP code-level tax rate trends across Castle Rock.
About Castle Rock Property Taxes
About Property Taxes in Castle Rock, Cowlitz, Washington
Castle Rock's median effective property tax rate of 0.80% is lower than the Washington state median of 0.92% and lower than the national median of 1.02%. This rate reflects the Cowlitz County base levy combined with local school district levies and Local improvement districts (LIDs) that vary by subdivision throughout the city.
Property tax rates are not uniform across Castle Rock. Homeowners in ZIP code 98611 carry a median effective rate of 0.80%, while those in 98611 pay 0.80%. This spread reflects how school district boundaries and local assessment districts are drawn across Cowlitz County. Understanding which part of Castle Rock you live in can make a meaningful difference to your annual tax bill.
Castle Rock homeowners who believe their assessed value is too high can file a formal appeal with the Tax Assessor before July 1, 2026.
If your estimated bill above seems higher than expected, Ownwell can review your assessment and protest on your behalf. You only pay if we save you money.
Property Tax Rates Across Castle Rock, Cowlitz County, Washington
As noted earlier, local government entities set tax rates, which can vary widely within a state.
Why? Because annually, each county estimates its required budget to provide services and divides that by the total value of all taxable property within its jurisdiction. This calculation results in the property tax rate.
While there are votes and laws involved in setting tax rates and budgets, in a nutshell, this is the annual process.
Below, you can compare Castle Rock's effective property tax rate to other cities in Washington and the median property tax rates in Washington and the U.S.
Our median effective property tax rate (tax bill ÷ assessor's market value) accounts for exemptions and deductions, making it more accurate than the general median tax rate, which is the midpoint of statutory rates before adjustments.
Median Effective Castle Rock Tax Rate
0.80%
Our median effective property tax rate (tax bill ÷ assessor's market value) accounts for exemptions and deductions, making it more accurate than the general median tax rate, which is the midpoint of statutory rates before adjustments.
Median Effective Cowlitz County Tax Rate
0.87%
Median Effective Washington Tax Rate
0.92%
Median Effective United States Tax Rate
1.27%
Property Tax Rates Across Castle Rock, Cowlitz County, Washington
| Zip | 10th Percentile | 25th Percentile | Median Tax Rate | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 98611 | 0.79% | 0.79% | 0.80% | 0.82% | 0.89% |
Source: Ownwell
Property Tax Assessment Values Across Castle Rock, Cowlitz County, Washington
When examining property taxes in Castle Rock, Washington, understanding the distinction between "market value" and "assessed value" is crucial.
The market value is what a willing buyer would pay to a willing seller in an open and competitive market, often influenced by location, property condition, and economic market trends. The Cowlitz County assessor estimates the market value for tax purposes.
The assessed value is the market value minus any applicable exemptions or limits determined by local laws and offerings. The tax assessed value is the figure used to calculate your property taxes or the amount multiplied by your tax rate to get your tax bill.
Assessment notices:
In Cowlitz County, assessment notices are sent in the spring each year. They'll typically reach your mailbox by the middle of May.
Each property owner receives an assessment notice that contains both the market value and assessed value, along with an estimate of your property tax bill. By providing insights into how assessed and market values are determined, this section helps property owners navigate their tax responsibilities and understand the valuation processes affecting their property taxes in Castle Rock.
For example, the median home price in Castle Rock is $369,030, with tax bills ranging significantly across the county. 98611 has the highest median home price at $369,030.
Property Tax Assessment Values Across Castle Rock, Cowlitz County, Washington
Source: Ownwell
$251,115
$353,353
$455,590
Median Castle Rock Market Value
$369,030
Median Cowlitz County Market Value
$341,430
Median Washington Market Value
$501,600
Median United States Market Value
$274,101
Property Tax Assessment Values Across Castle Rock, Cowlitz County, Washington
| Zip | 10th Percentile | 25th Percentile | Median Home Price | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 98611 | $123,918 | $260,438 | $369,030 | $506,415 | $637,454 |
Source: Ownwell
Property Tax Bills Across Castle Rock, Cowlitz County, Washington
Property tax bills in Castle Rock are based on the assessed value of a home and the local tax rates set by taxing authorities in Cowlitz County. When a property’s market value rises, the assessed value can increase too, which can lead to a higher tax bill. For a home with a median price of $369,030, the tax bill can vary widely depending on the property’s assessment and the specific levies applied.
In Castle Rock, the median property tax bill is $2,929, which is above the national median property tax bill of $2,400. Homeowners at the 25th percentile pay $1,896, while those at the 75th percentile pay $4,112 and the 90th percentile pay $5,269. These differences show how location, assessed value, and local tax rates can affect what homeowners owe each year.
Median Castle Rock Tax Bill
$2,929
Median Cowlitz County Tax Bill
$2,984
Median Washington Tax Bill
$4,512
Median United States Tax Bill
$3,209
Property Tax Bills Across Castle Rock, Cowlitz County, Washington
| Zip | 10th Percentile | 25th Percentile | Median Tax Bill | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 98611 | $488 | $1,896 | $2,929 | $4,112 | $5,269 |
Source: Ownwell
Don't miss the deadline to appeal!
Dates | |
|---|---|
| Appeal Deadline | July 1 |
| Tax Bill | |
| Issued | February 10 |
| Due Date #1 | April 30 |
| Due Date #2 | October 31 |
Links | |
|---|---|
| Cowlitz Tax Assessor | |
| Website | cowlitzinfo.net |