California vs Washington gas prices
Regular gas is $0.46 a gallon cheaper in Washington — $6.97 on a 15-gallon fill-up.
| Grade | CA | WA | Diff. | |
|---|---|---|---|---|
| Regular | $6.04 | $5.58 | $0.46WA | Washington |
| Midgrade | $6.27 | $5.84 | $0.43WA | Washington |
| Premium | $6.46 | $6.09 | $0.37WA | Washington |
| Diesel | $8.27 | $7.31 | $0.95WA | Washington |
Is cheaper gas worth the detour?
Use your tank and extra travel costs. Prices below are AAA state averages as of 2026-09-16; check the actual station prices before driving.
Extra distance and time include the return to your original route. Detour fuel uses the higher state price. Tire wear and maintenance are excluded. This estimates a price difference; it does not verify a station offer or route.
Where the $0.46 gap actually comes from
80% of it is tax. California charges $0.37 more per gallon in federal and state taxes than Washington. The remaining $0.09 is a real difference in what the fuel, refining and distribution cost — refinery proximity, pipeline access and state fuel-blend rules.
Fuel, refining, distribution and marginFederal and state taxes Pre-tax figures are estimates — see the note below.
What the gap is worth
Based on today’s $0.46 per-gallon difference, which moves week to week. Use the fuel cost calculator for your own mileage and vehicle.
Prices by metro area
State averages hide a lot. These are the cheapest metros AAA reports on each side.
Other comparisons
Frequently asked questions
Is gas cheaper in California or Washington?
Regular gas is cheaper in Washington, at $5.58 a gallon against $6.04 in California — a gap of $0.46, or 7.7%. On a 15-gallon fill-up that is $6.97. Figures are AAA daily state averages for 2026-09-16.
Why is gas more expensive in California?
80% of the $0.46 gap is tax rather than the cost of the fuel. California levies $0.37 more per gallon in federal and state taxes; the remaining $0.09 is a genuine difference in what the fuel, refining and distribution cost.
Is diesel cheaper in California or Washington?
Diesel is cheaper in Washington at $7.31 a gallon, against $8.27 in California — $0.95 a gallon apart.
Why this price is what it is
- Why Is Gas So Expensive in California? The Full 2026 BreakdownCalifornia averages $6.04/gal — 61% more than Indiana at $3.75. Taxes, the CARB blend, refinery isolation and climate fees, with today's AAA figures.
- Fuel Taxes Explained: What You Really Pay Per GallonA big slice of every gallon is tax — but how much, and where does it go? A clear guide to federal, state and European fuel taxes.
- Premium vs. Regular Gas: Is Premium Actually Worth It?Premium costs more per gallon — but does it help your car? Here's when premium is worth it, when it's wasted money, and what octane really does.