Castle Rock Sales Tax Calculator
The combined sales tax rate in Castle Rock, Washington is 7.9% in 2026 — a 6.5% Washington state rate plus 1.4% in local add-ons. That is the 13th lowest rate of the 280 Washington cities we track, and it runs below Washington's 9.47% average. On a $100 purchase that's $7.90 in tax for a $107.90 total.
$100.00 total
Before tax: $100.00 · Sales tax: $0.00 (0%)
State & average combined rates: Tax Foundation 2026. Local rates vary by city/county — adjust the rate for an exact figure. How we calculate →
Castle Rock sales tax rate in 2026
Castle Rock charges a combined sales tax rate of 7.9%: the Washington statewide base of 6.5% plus 1.4% in city and county add-ons. Castle Rock is in Cowlitz County.
That local add-on is set by Castle Rock and the taxing districts that overlap it, which is why neighboring cities in Washington can charge a different total even a few miles apart.
Castle Rock vs the rest of Washington
At 7.9%, Castle Rock runs below Washington's 9.47% statewide average combined rate by 1.57%. Among the 280 Washington cities we track by combined rate, Castle Rock ranks the 13th lowest.
That makes Castle Rock comparatively light on sales tax for Washington, though it's still well above zero.
Sales tax examples in Castle Rock
At Castle Rock's 7.9% combined rate:
$100 → $7.90 tax, $107.90 total · $1,000 → $79.00 tax, $1,079.00 total · $25,000 car purchase → $1,975 tax, $26,975 total.
Working backwards: a $1,080.00 receipt total in Castle Rock means the pre-tax price was $1,000.93 and $79.07 was tax — use “Remove tax” mode above to reverse any total instantly.
A note on Castle Rock's exact rate
The 7.9% rate applies within Castle Rock's official city limits as published by Washington DOR — Tax Rate Lookup. Addresses with a Castle Rock mailing address but outside the incorporated city line — a common situation on the edges of any city — can fall under a different, usually lower, rate.
For an address-exact rate, use the official lookup tool: Washington DOR — Tax Rate Lookup. This calculator pre-fills the published city-limits rate as a reliable starting point.
Castle Rock sales tax — frequently asked questions
What is the sales tax rate in Castle Rock, Washington?
Castle Rock's combined sales tax rate is 7.9% in 2026 — 6.5% Washington state tax plus 1.4% in local add-ons. That's the 13th lowest rate of the 280 Washington cities we track.
How much is sales tax on $100 in Castle Rock?
At Castle Rock's 7.9% rate, sales tax on a $100 purchase is $7.90, for a $107.90 total.
How much sales tax will I pay on a $25,000 car in Castle Rock?
At Castle Rock's 7.9% combined rate, sales tax on a $25,000 vehicle purchase is about $1,975, for a $26,975 total before any trade-in credit or registration fees.
Is Castle Rock's sales tax higher or lower than the Washington average?
Castle Rock runs below Washington's 9.47% statewide average by 1.57%, ranking the 13th lowest of the 280 Washington cities we track.
How do I calculate sales tax backwards from a total in Castle Rock?
Divide the total by 1 plus the rate. A $1,080.00 total in Castle Rock works back to a $1,000.93 pre-tax price and $79.07 of tax. Use “Remove tax” mode above to do this automatically.
Does Castle Rock's sales tax rate apply everywhere in the Castle Rock area?
The 7.9% rate applies within Castle Rock's official city limits. Nearby addresses outside the incorporated boundary can be taxed at a different rate — check Washington DOR — Tax Rate Lookup for an address-exact figure.
Compare nearby cities in Washington
See all 280 Washington cities ranked by combined sales tax rate, or compare:
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