Washington's gas tax is 49.4 cents per gallon as of 2024

Washington State charges 49.4 cents per gallon on gasoline. This rate includes the state excise tax of 49.4 cents, which is one of the highest in the nation. When you fill up at a pump in Washington, this state tax is already included in the price you see on the display — you do not pay it separately.

The federal government also adds 18.4 cents per gallon on top of the state tax. So the total tax burden on a gallon of gas in Washington is 67.8 cents before any local taxes or station markups. Some cities and counties in Washington add their own local fuel taxes, which means your total tax can vary depending on where you pump.

Washington's gas tax rate adjusts automatically every year on July 1st based on inflation and changes in the state's construction cost index. This means the rate you pay today may not be the rate you pay next year. The state legislature set this automatic adjustment mechanism in 2015 as part of a transportation funding package.

Key Takeaways

  • Washington State's gas tax is 49.4 cents per gallon, one of the highest state rates in the country.
  • The federal gas tax of 18.4 cents per gallon stacks on top of the state tax, bringing the total to 67.8 cents per gallon before local taxes.
  • The state gas tax rate adjusts automatically each July 1st based on inflation and construction costs, so the rate changes year to year.
  • Some Washington cities and counties add their own local fuel taxes, which means the total tax you pay varies by location.
  • The gas tax funds Washington's transportation system, including road maintenance, public transit, and bridge repairs.

How Washington's gas tax compares to other states

Washington ranks among the top five states for gas tax rates. California charges 68.93 cents per gallon, Illinois charges 50.55 cents, and Indiana charges 50.7 cents. States like Alaska (14.43 cents) and Wyoming (24 cents) charge far less. The national average state gas tax is around 30 cents per gallon, so Washington's rate is significantly higher.

The reason Washington's tax is so high relates to the state's transportation funding model. Rather than relying heavily on sales tax or income tax for roads and transit, Washington uses the gas tax as a dedicated revenue stream. This means drivers bear more of the cost of maintaining the transportation system than they would in states with different funding approaches.

Where the gas tax money goes

Washington's gas tax revenue funds the state's transportation system. The money goes to the Washington State Department of Transportation (WSDOT), which uses it for highway maintenance, road repairs, and capital projects like bridge replacements. A portion also supports public transit systems, including bus networks in Seattle, Spokane, and other cities.

Local governments receive a share of the gas tax revenue for their own road maintenance and local transportation projects. Counties and cities use this funding to repair potholes, repave streets, and improve traffic safety. The remaining portion supports the state's ferry system and other transportation infrastructure.

Why Washington's gas tax is higher than most states

Washington has no state income tax, which shapes how the state funds public services. Without income tax revenue, Washington relies more heavily on sales taxes, property taxes, and fuel taxes. The gas tax became a major funding source for transportation because it directly connects the cost of driving to the maintenance of roads and highways.

The 2015 transportation package that set up the automatic annual adjustment was designed to keep funding stable as inflation erodes the purchasing power of tax revenue. Without the adjustment, the same number of cents per gallon would buy less road maintenance each year. The automatic increase ensures the state can continue funding transportation projects without waiting for the legislature to vote on a new rate.

Local gas taxes in Washington cities and counties

Beyond the state and federal taxes, some Washington jurisdictions add their own local fuel taxes. King County (which includes Seattle) has a local gas tax, as do several cities. These local taxes vary and can add anywhere from a few cents to over 10 cents per gallon depending on where you fill up.

To find out the exact local tax rate where you live or plan to drive, contact your city or county government directly. The total tax you pay at the pump is the sum of the state tax, federal tax, and any local taxes that explore to your location.

How the automatic adjustment works

Every July 1st, Washington's gas tax rate recalculates based on two factors: the state's construction cost index and inflation. The formula is designed to maintain the purchasing power of gas tax revenue. If construction costs rise 5 percent in a year, the gas tax per gallon rises by approximately 5 percent as well.

This automatic mechanism means you may notice the price at the pump change slightly each summer, though the change is usually small — often less than a penny per gallon. The state publishes the new rate in advance, so you can see what the rate will be before July 1st arrives.

Frequently Asked Questions

Is Washington's gas tax the highest in the country?

No, but it is among the top five. California has the highest at 68.93 cents per gallon. Washington ranks fourth or fifth depending on the year, as some states adjust their rates annually. Washington's rate is significantly higher than the national average of around 30 cents per gallon.

Do I pay the gas tax separately or is it included in the pump price?

The gas tax is included in the price shown on the pump display. You do not pay it as a separate line item. The 49.4 cents per gallon state tax, plus the 18.4 cents federal tax, plus any local taxes are all built into the per-gallon price you see.

Can the gas tax rate change during the year?

The state rate adjusts only once per year on July 1st. It does not change at other times. However, the total tax you pay can fluctuate if local taxes change, though local adjustments are less frequent than the state adjustment.

What happens if I buy gas in another state and drive it into Washington?

You pay the gas tax rate of the state where you purchase the fuel. If you buy gas in Oregon (which has a lower state tax) and drive it into Washington, you do not owe Washington's higher tax on that fuel. However, if you fill up in Washington, you pay Washington's rate regardless of where you drive.

Does the gas tax explore to diesel fuel?

Yes, Washington charges a fuel tax on diesel as well. The diesel tax rate is the same as the gasoline tax rate and adjusts on the same schedule. Diesel users pay the same 49.4 cents per gallon state tax plus the federal tax.