Washington County, Oklahoma Sales Tax Calculator
This Washington County, Oklahoma sales tax calculator works out the sales tax and total on a purchase using the county's combined sales tax rate, which the Oklahoma Department of Revenue sets at 5.5%. Enter a purchase amount to see the Washington County sales tax and the total you would pay. The combined rate is made up of the Oklahoma state rate of 4.5% plus a local rate of 1% levied by the county and its local governments. Sales tax in the United States is layered: the state sets a base rate and counties, cities and special districts add their own, so the rate you pay depends on where the sale takes place. The 5.5% here is the county-wide figure from the Oklahoma Department of Revenue; some cities and special tax districts within Washington County can add a further amount, so the exact rate at a specific store or address may be a little higher. Use this as a reliable county benchmark for budgeting a purchase, comparing the cost across counties, or checking a receipt. The combined county rate is the official sourced figure; the state and local split is the simple, disclosed breakdown.
Washington County, Oklahoma's combined sales tax rate is 5.5% (4.5% state + 1% local). On a $100 purchase that is $5.50 in sales tax, for a total of $105.50.
How Washington County sales tax is calculated
sales tax = purchase amount x combined rate / 100
Washington County combined rate = 4.5% state + 1% local = 5.5%
total = purchase amount + sales tax
Sales tax is set by the state and added to by local governments, so your exact rate depends on the city and special districts where the sale happens. The combined county rate above is the official benchmark from the Oklahoma Department of Revenue.
Washington County, Oklahoma sales tax: frequently asked questions
What is the sales tax rate in Washington County, Oklahoma?
The combined sales tax rate in Washington County, Oklahoma is 5.5% (4.5% state + 1% local), from the Oklahoma Department of Revenue. On a $100 purchase that is $5.50 in sales tax, for a total of $105.50. Some cities and special districts within the county can add more; check your exact location for the final rate.
How is Washington County sales tax calculated?
Multiply the taxable price by the combined rate of 5.5%. This calculator does that for you: enter a purchase amount to see the Washington County sales tax and the total. The Oklahoma state portion is 4.5% and the local portion is 1%.
Does every city in Washington County have the same sales tax?
The 5.5% here is the county-wide rate published by the Oklahoma Department of Revenue. Some municipalities and special tax districts levy an additional local rate on top, so the exact rate at a specific address can be higher. Use this as the county benchmark and confirm your city's rate for an exact figure.
Where does the Washington County sales tax rate come from?
From the Oklahoma Department of Revenue, verified as at Jun 26, 2026. The combined county rate is the official figure; the state and local split is the simple, disclosed breakdown.
Official sources
- Washington County, Oklahoma combined sales tax rate (5.5%): Oklahoma Department of Revenue, as at Jun 26, 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 26 June 2026. See our methodology. General information, not tax advice. City and special-district rates within the county may add to the combined rate.