Chart

Most of Washington's $1 gas premium is state policy

Stacked bar chart of how many cents a gallon Washington gas cost above the U.S. average each year from 2015 to 2026. From 2015 to 2022 the gap was 27 to 63 cents, about 21 cents of it higher state gas taxes. After the carbon market started in 2023 the gap grew to 94 cents in 2023, 76 in 2024, 103 in 2025 and 108 in 2026: 26 cents higher state gas taxes, an estimated 43 cents carbon market and 39 cents of refining, supply, station and other costs.

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Washington gas cost 45 cents a gallon more than the U.S. average from 2015 to 2022 and $1.08 more in 2026. In 2026, 26 cents of the gap is Washington's higher state gas taxes (its 56.5-cent gas tax against the average state's 28.7 cents) and an estimated 43 cents is its carbon market, together about two-thirds; the other 39 cents is West Coast refining, supply, station costs and other factors. Source: EIA weekly prices and state tax tables; FactHub carbon-market estimate.

How much more a gallon of regular gas cost in Washington than the U.S. average each year, 2015-2026, in cents: Washington's higher state gas taxes, the estimated cost of its carbon market (since 2023), and everything else (refining, supply, stations and other costs).

Credit: FactHub Research Team; data from U.S. EIA and FactHub's carbon-market estimate

What this chart asks

How much more does Washington gas cost than the U.S. average, and why?

Why it is shown this way

  • Stacked bars show each year's total gap and what it is made of.
  • The two state-policy parts sit at the bottom in color, so their combined height reads from zero; everything else is gray on top.
  • The years before 2023 show the gap before the carbon market, which skeptics on both sides ask for.

Chart annotations

These markers provide relevant context for interpreting the chart. Their timing or position does not, by itself, establish causation.

Carbon market starts
2023

Why this is marked: Washington's cap-and-invest program (Climate Commitment Act) began covering fuel suppliers on January 1, 2023.

Data and accessibility

The chart's data and images are in the strip under it.

Dataset wa-gas-price-premium-2015-2026, analysis premium-parts

Sources

This chart draws on the sources of the dataset versions it visualizes.

Why Washington gas costs more than the U.S. average, 2015-2026

  1. U.S. Energy Information Administration, Weekly Retail Gasoline Prices, regular all formulations: Washington (EMM_EPMR_PTE_SWA_DPG) and U.S. (EMM_EPMR_PTE_NUS_DPG) Weekly Washington and U.S. average retail prices of regular gasoline, all taxes included, 2015-2026.

    Retrieved November 8, 2026. Public domain (U.S. government work). Allowed; EIA asks to be cited.

    Reliability: Government. EIA samples retail outlets at 8 a.m. each Monday; prices include all taxes.

  2. U.S. Energy Information Administration, Federal and state motor fuels taxes (fueltaxes.xlsx), sheets January 2015 through July 2026 (revised) Washington's total state gasoline taxes and fees and EIA's average of the states, January 1 and July 1 of each year.

    Retrieved November 2, 2026. Public domain (U.S. government work). Allowed; EIA asks to be cited.

    Reliability: Government. Compiled by EIA twice a year from state statutes and agencies. Excludes county and local taxes.

Limitations

  • The carbon-market part is FactHub's estimate (published range 24-46 cents since 2023), from FactHub's dataset on Washington's gasoline price premium and the Climate Commitment Act, which this chart's dataset is built from. Ecology's contracted study found 7-24 cents in 2024, and full pass-through of the June 2026 auction price would be about 52 cents.
  • The state-tax part is the gas tax: 56.5 cents a gallon in Washington on July 1, 2026, against 28.7 cents in the average state. Washington's other state taxes and fees on gasoline (mostly the hazardous substance tax) were 3.7 cents, 2.1 cents below the average state's, partly because several states tax gas sales and Washington doesn't.
  • Everything else is a remainder: West Coast crude, refining and shipping costs, outages, station costs and margins, local taxes, and Washington's petroleum products tax (about 0.7 cents). Washington publishes no refiner margin data, so it can't be split further.
  • 2026 runs January 5 to November 2. The Iran war raised prices everywhere from March 2026; Washington's gap was about 95 cents before it and $1.10 after.
  • Cents of each year, not adjusted for inflation.

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