IFTA Tax Rates in California (2026)
California's IFTA diesel rate is 97.9 cents per gallon — the highest in the nation and roughly triple the average state. Here is what is inside that number, how it lands on your quarterly return, and the border fueling plays that decide whether it hurts or just stings.
By the HaulMath editorial team · Updated $1
Key numbers at a glance
| Fuel type | Rate | Notes |
|---|---|---|
| Diesel (IFTA rate) | 97.9¢/gal ($0.979) | The single highest IFTA rate in the nation as of Q4 2026; one line on your return |
| — Diesel fuel tax component | 48.2¢/gal ($0.482) | Excise tax effective July 1, 2026, up from 46.6 cents; adjusts each July 1 with CPI |
| — Diesel sales tax component | 49.7¢/gal ($0.497) | The diesel sales tax converted to cents per gallon for IFTA reporting; moves with fuel prices |
| Gasoline (context) | 63.4¢/gal excise ($0.634) | Paid at the pump effective July 1, 2026; no gasoline rate appears on California's IFTA matrix row |
Everything about California IFTA is scale: the biggest port complex in the country, the longest stretches of I-5 and I-10, and a diesel tax rate no other jurisdiction comes close to. The rate is not one tax but two stacked together, which is why it changes more often than most. The figures below come from the official IFTA Inc. fourth quarter 2026 tax rate matrix and the CDTFA fuel tax rates page — as of Q4 2026 — always confirm the current quarter's official IFTA matrix before filing (this quarter's matrix is not final until December 4, 2026). All 50 states compared side by side are on the IFTA rates by state hub.
IFTA tax rates in California
California's IFTA rate applies to diesel only — the state's row in the IFTA matrix shows no gasoline rate — and it combines two components per CDTFA:
| Fuel type | Rate | Notes |
|---|---|---|
| Diesel (IFTA rate) | 97.9¢/gal ($0.979) | The single highest IFTA rate in the nation as of Q4 2026; one line on your return |
| — Diesel fuel tax component | 48.2¢/gal ($0.482) | Excise tax effective July 1, 2026, up from 46.6 cents; adjusts each July 1 with CPI |
| — Diesel sales tax component | 49.7¢/gal ($0.497) | The diesel sales tax converted to cents per gallon for IFTA reporting; moves with fuel prices |
| Gasoline (context) | 63.4¢/gal excise ($0.634) | Paid at the pump effective July 1, 2026; no gasoline rate appears on California's IFTA matrix row |
| Biodiesel / renewable diesel blends | 97.9¢/gal ($0.979) | Reported as diesel on the California line |
Two mechanics matter. First, the excise piece resets every July 1 on the California Consumer Price Index, so the rate you use in Q3 can differ from the one you used in Q1 — 46.6 cents became 48.2 on July 1, 2026. Second, the sales tax piece floats with diesel prices and location, which is why CDTFA publishes the combined figure IFTA carriers actually file. There is no separate surcharge schedule like Indiana's — everything sits in the one 97.9-cent number, which is both simpler to file and harder to pay.
How California IFTA affects your filings
Your California line each quarter is California miles divided by fleet MPG, times $0.979 for diesel. Take a Barstow to Las Vegas leg doubling back into Arizona at 6.5 MPG:
| State | Miles | Gallons at 6.5 MPG | Diesel rate | Tax owed |
|---|---|---|---|---|
| California | 250 | 38.5 | $0.979 | $37.65 |
| Nevada | 150 | 23.1 | $0.270 | $6.23 |
| Arizona | 200 | 30.8 | $0.260 | $8.00 |
| Total | 600 | 92.3 | — | $51.88 |
California is 42% of the miles but 73% of the tax. Now flip the fueling. Buy all 92.3 gallons in California and you prepaid $90.37 against $51.88 owed — a $38.49 refund, which is money you lent Sacramento interest-free until the return clears. Buy them all in Arizona and you prepaid $24.00 against $51.88 owed, leaving $27.88 due. Neither extreme is optimal; the disciplined play is buying high-rate gallons where the rate is high but keeping total California purchases lean. Model your own lane mix in the IFTA calculator and use the quarter's matrix — in a 97.9-cent state, filing on a stale rate multiplies error fast.
If California is your base state, your IFTA license comes through CDTFA's IFTA/DI program, and the same quarterly deadlines apply as everywhere else — April 30, July 31, October 31 and January 31, with late penalties typically $50 to $100 plus interest per quarter.
Fueling strategy around California: price minus tax
Shop by net price: pump price minus the tax, plus the rates ahead. California's neighbors — Arizona 26.0 cents, Nevada 27.0 cents, and Oregon's weight-mile system in place of a per-gallon tax — turn every border into an arbitrage line. Crossing the Colorado River at Blythe or Needles or entering from Nevada at Primm or Barstow, arrive with full tanks: each hundred gallons bought in Arizona instead of California is roughly $71.90 less prepaid tax. Inside California, buy only what the range and the return legs require — the legal minimum plus a safety margin — because every California gallon carries that 97.9-cent rate in it. Owner-operators running regular I-5 or I-10 lanes can move four figures a year this way. Then make sure your freight pays for it: California diesel benchmarks drive the surcharge math in the fuel surcharge guide, and the surcharge should cover the pump, not the IFTA account.
FAQ
What is the current IFTA diesel tax rate in California?
As of Q4 2026, California's IFTA rate for diesel is 97.9 cents per gallon, per the official IFTA Inc. tax rate matrix — the highest of any jurisdiction. It combines the $0.482-per-gallon diesel excise tax effective July 1, 2026 with a 49.7-cent diesel sales tax component. Always confirm the current quarter's official IFTA matrix before filing.
Why is California's IFTA diesel rate so much higher than other states?
California's rate stacks two taxes: the diesel fuel tax, 48.2 cents per gallon after the July 1, 2026 CPI adjustment (up from 46.6 cents), plus the state diesel sales tax converted into a cents-per-gallon rate of 49.7 cents for IFTA purposes. Most states charge excise only, which is why the nearest competitor is well under 80 cents.
Does California report a gasoline rate on the IFTA return?
No — California's row in the IFTA tax matrix shows no gasoline rate; the IFTA/interstate program applies to diesel. Gasoline sold in California carries the 63.4-cent-per-gallon excise at the pump (effective July 1, 2026), but gasoline is not the fuel semis file on. Confirm specifics with CDTFA if you run gasoline-powered qualified vehicles.
How do I calculate the fuel tax owed for miles driven in California?
Taxable gallons = California miles divided by your truck's MPG. Tax owed = taxable gallons times $0.979 (Q4 2026). At 6.5 MPG, 250 California miles burn 38.5 gallons and owe about $37.65 to California — more than Nevada and Arizona combined on a typical three-state run.
Where should I buy fuel around California to lower my IFTA bill?
Arizona diesel is 26.0 cents and Nevada 27.0 cents versus California's 97.9 — cross the border with full tanks and buy the minimum you need inside California. Every hundred gallons purchased in Arizona or Nevada instead of California saves roughly $71 in tax timing.
Does California have an IFTA surcharge tax like Indiana or Virginia?
Not as a separate line. California's sales tax component is already baked into the single 97.9-cent IFTA diesel rate, so unlike Indiana or Virginia there is no second schedule to file — but the total is the highest in the nation.