Updated July 28, 2026 - AAA daily average
Diesel Cost per Gallon in Washington (2026)
$6.13/GAL
+1.00 vs US average ($5.13)Rank #48 of 50 statesPADD 5
Diesel Tax Breakdown
Federal diesel excise tax24.4c/gal
Washington state diesel tax49.4c/gal
Total tax73.8c/gal
Tax as % of price12%
Sources: Federation of Tax Administrators, EIA. Rates as of April 2026.
CALCULATE YOUR FUEL COST IN WASHINGTON
Use our trip calculator prefilled at $6.13/gal for Washington.
Sources: State diesel average from AAA Gas Prices (gasprices.aaa.com), July 28, 2026; US average and PADD context from the EIA Weekly On-Highway Diesel Fuel Survey (July 20, 2026); state tax from the Federation of Tax Administrators diesel tax table. State prices are representative averages; actual pump prices vary by retailer and location.