Diesel Prices in California: Weekly Trucking Fuel Cost and Surcharge (2026)
Diesel in California averaged $8.039 a gallon for the week of 14 September 2026, according to the Energy Information Administration's weekly survey of on-highway diesel prices. That is up 27.5 cents on the week, up $3.068 on a year earlier, and $1.754 above the U.S. average of $6.285.
By Small Fleet HQ | Updated
Diesel prices in California, week of 14 September 2026
Prices are for the week of .
The figure is EIA's California series, a volume-weighted average of cash self-serve prices with taxes included. It covers California alone.
| Measure | California | U.S. average |
|---|---|---|
| This week | $8.039 | $6.285 |
| Change on the week | up 27.5 cents | up 31.8 cents |
| Change over four weeks | up $1.254 | up 83.1 cents |
| Same week a year earlier | $4.971 | $3.739 |
| 52-week high | $8.039, 14 September 2026 | $6.285, 14 September 2026 |
| 52-week low | $4.613, 12 January 2026 | $3.459, 12 January 2026 |
California is the most expensive of EIA's ten regions this week. Over the last 52 weeks it averaged $1.400 above the U.S. average. This week is the highest price in the series, which starts on 3 July 1995.
The trend in California over two years
The chart shows California against the U.S. average for the last 104 weeks. Move a pointer across it, or focus it and use the arrow keys, to read any week.
Fuel surcharge in California
The calculator starts from California's price this week. Swap in the series your contract names, then enter its base price and miles per gallon.
Enter your contract terms
How it adds up
The starting base price of $1.25 is an example, and 7.28 miles a gallon is the average ATBS reported for its owner-operator clients in 2025. On a 500-mile load, the regional and national prices give different answers:
| Contract reads | Price | Surcharge a mile | On 500 miles |
|---|---|---|---|
| California price | $8.039 | $0.933 | $466.50 |
| U.S. average | $6.285 | $0.692 | $346.00 |
This week a surcharge on the U.S. average pays $120.50 less on that load than one on California's price. The truck burns about 68.7 gallons either way, roughly $552.28 at California's average pump price.
Diesel price before taxes in California
Every price above includes the federal diesel tax of $0.244 a gallon and state taxes. The table takes both off California's price for each state it covers, using the diesel columns of EIA's July 2026 (revised) tax table.
| State | State diesel tax | Taxes and fees in total | Price before taxes |
|---|---|---|---|
| California | $0.482 | $0.929 | $6.866 |
What EIA counts in each state's taxes and fees
- California. 2.25% state sales tax on gasoline, 13.00% state sales tax on diesel (prepaid rates for these sales taxes: gasoline $0.0800/gal; diesel $0.4250/gal). Additional District sales taxes may apply. State Underground Storage Tank fee (all products): $0.02/gal. Oil Spill Prevention and Administration (OPSA) Fee (all products): $0.0990 per barrel ($0.0024/gal). Gasoline and diesel are also subject to costs associated with the Low Carbon Fuel Standard and Cap-and-Trade programs.
Those state taxes are what your IFTA return settles, by the miles you run in each state. To set California beside every other region, see diesel prices by region.
Why California has its own price
California is the only state for which EIA publishes a weekly diesel series. Every other state falls inside a regional average. California is part of EIA's West Coast series, which also covers the West Coast outside California.
- Diesel Prices in the West Coast: Weekly Trucking Fuel Cost and Surcharge (2026)
- Diesel Prices in the West Coast Outside California: Weekly Trucking Fuel Cost and Surcharge (2026)
Method: how each number was obtained
- The weekly prices are EIA's California on-highway diesel series, all types, in dollars a gallon, read from EIA's history table each day so that revisions carry over.
- EIA collects the cash self-serve price, taxes included, as of 8:00 a.m. local time each Monday.
- Federal and state diesel taxes and fees come from EIA's federal and state motor fuels tax table.
- Changes, highs and lows, gaps to the U.S. average, rank, surcharge figures and prices before taxes are our arithmetic on those figures.
The page updates only when EIA's figures change. Pages across the site follow our rating methodology.
What we could not verify
- County and local fuel taxes, and state taxes on gross or net receipts, which EIA's tax table leaves out.
- The price at any single truck stop in California, which can sit well away from the regional average.
- The base price and fuel economy in your own surcharge program.
Sample, window and limitations
The California series starts on 3 July 1995. EIA changed its survey sample on 13 June 2022 and says prices from that week on are not directly comparable with earlier weeks. The chart shows two years and the table one.
How to cite this
Small Fleet HQ, "Diesel Prices in California: Weekly Trucking Fuel Cost and Surcharge (2026)", updated September 16, 2026, https://smallfleethq.com/fuel-cards/diesel/california. Price data: U.S. Energy Information Administration, weekly retail on-highway diesel prices, California, week of 14 September 2026.
Frequently asked questions
EIA's average retail on-highway diesel price for California was $8.039 a gallon for the week of 14 September 2026, up 27.5 cents on the week before and above the U.S. average by $1.754.
California is the only state with its own weekly EIA diesel series.
It depends on your contract. With California's price of $8.039, a $1.250 base price and 7.28 miles a gallon, the surcharge comes to $0.933 a mile. A contract that reads the U.S. average uses $6.285 instead, so check which series yours names.
California's diesel taxes and fees total $0.929 a gallon in EIA's latest table, on top of the $0.244 federal tax.
Sources & References (6)
U.S. Energy Information Administration, Gasoline and Diesel Fuel Update, weekly retail on-highway diesel prices
eia.gov ↗U.S. Energy Information Administration, Weekly Retail Gasoline and Diesel Prices, history tables by region
eia.gov ↗U.S. Energy Information Administration, On-Highway Diesel Fuel Price Survey methodology
eia.gov ↗U.S. Energy Information Administration, definitions for retail gasoline and diesel prices, including the PADD regions
eia.gov ↗U.S. Energy Information Administration, Federal and state motor fuels taxes, July 2026 (revised) edition
eia.gov ↗Todd Dills, "Owner-op income up, with 'capacity-driven' trucking recovery ongoing, fuel-cost wildcard", Overdrive, 26 March 2026 (ATBS 2025 fuel economy)
overdriveonline.com ↗