Verified April 2026
How to Calculate Sales Tax in Columbia, Washington
2026 Step-by-Step Guide for Businesses & Consumers
Current Columbia Sales Tax Rate
| Jurisdiction | Rate |
|---|---|
| Washington State Sales Tax | 6.500% |
| County Sales Tax | 1.700% |
| Total Combined Rate | 8.200% |
How to Calculate Sales Tax in Columbia
-
1
Find the combined rate
The combined sales tax rate in Columbia is 8.200%. This equals: Washington state rate of 6.500% + County 1.700%.
-
2
Convert the percentage to a decimal
8.200 ÷ 100 = 0.0820
-
3
Multiply by your purchase amount
Example: $100.00 × 0.0820 = $8.20 in sales tax
-
4
Add tax to the original price
$100.00 + $8.20 = $108.20 total cost
What's Taxable in Washington?
Most tangible personal property is taxable in Washington. Check with the
Washington Department of Revenue for specific exemption categories.
Do You Have Nexus in Washington?
Economic Nexus Threshold
If your business has over $100,000 in annual
Washington sales or 200 transactions,
you are required to collect and remit Washington sales tax. This applies to out-of-state remote sellers too.
Expert Sales Tax Tips for Columbia
Out-of-State Sellers
Selling into Washington from out of state? Register before you cross the $100,000 threshold to avoid back taxes and penalties.
Frequently Asked Questions
Sales Tax Calculator
Using 8.200% rate for Columbia
$
Tax Amount
$0.00
Total with Tax
$100.00
Rate applied: 8.200% combined