Idaho Gas Prices and Why They Are What They Are
Prices as of September 22, 2026, per AAA · Updated September 24, 2026
As of September 22, 2026, regular gasoline in Idaho averages $4.97/gallon (the 7th-highest in the U.S.), per AAA. $0.49 above AAA's national average of $4.47 on 2026-09-22. State fuel taxes and fees are 33.0 cents per gallon (Tax Foundation, 2026 edition). Federal gasoline tax adds 18.4 cents per gallon.
How Idaho got here
Weekly snapshots of AAA state averages, recorded by this site since July 6, 2026. AAA state averages.
Where the $4.97 goes
| Component | $/gallon | Share | Source |
|---|---|---|---|
| Monthly WTI crude proxy | $2.00 | 40.2% | EIA monthly WTI |
| Federal and Idaho fuel taxes | $0.51 | 10.3% | Tax Foundation, 2026 edition |
| Unallocated residual (after the monthly WTI crude proxy and taxes) | $2.46 | 49.4% | computed; not attributed to components |
The crude-oil share of the price is set by a world market that every state's refiners buy from; the differences between states come from taxes, fuel specifications, and refining and distribution costs. EIA: factors affecting gasoline prices.
Why Idaho is above the U.S. average
Taxes and supply costs
Idaho's state fuel tax ranks 19 among the 50 states (Tax Foundation, 2026 edition). The crude-oil share of the price is set by a world market that every state's refiners buy from; the differences between states come from taxes, fuel specifications, and refining and distribution costs. The amount after the crude proxy and taxes is the unallocated residual after crude and taxes.
What a gallon costs in work time
At Idaho's median hourly wage of $23.06 (BLS OEWS, May 2025), a gallon of regular costs 12.9 minutes of work. BLS OEWS. Compare gasoline affordability.
State policies that show up at the pump
| Policy or supply base | Detail | Source |
|---|---|---|
| Refining base | 0 operating refineries, 0 b/d (EIA Refinery Capacity Report 2026, as of 2026-01-01) | Source |
State government control
| Control in 2026 | Unified Republican |
| Years of unified Democratic control, 2001–2026 | 0 |
| Years of unified Republican control | 26 |
| Years of split government | 0 |
Party control by year from Ballotpedia, compiled 2026-09-08; counts computed at build. Ballotpedia.
Questions people ask
How does Idaho compare with the U.S. this week?
$0.49 above AAA's national average of $4.47 on 2026-09-22.
What share of the price is tax?
Combined state and federal taxes are 10.3% of regular (Tax Foundation, 2026 edition).
What does diesel cost in Idaho?
AAA diesel averages $6.59 as of September 22, 2026.
Compare: all states ranked · Idaho electricity rates · gasoline prices by country · refining · why gas prices are high.
Sources: AAA (pump prices), Tax Foundation, 2026 edition, EIA federal gasoline tax, EIA monthly WTI, EIA weekly retail gasoline, and BLS OEWS. The residual is computed, not attributed to components. See methodology.