Gas prices in Idaho today
Regular gasoline in Idaho averages $4.00 per gallon as of Monday, July 13, 2026, 13 cents per gallon above the US national average of $3.87 [EIA · 13 Jul 2026]. On-highway diesel is $4.71, -17 cents off the national diesel mean of $4.88. Idaho rack feeds from Salt Lake refining; Boise prints cheaper than Oregon by 30 to 70 cents most days.
Source: [AAA · 13 Jul 2026] · State excise: 33.0 cents/gal · PADD 4
Idaho's pump-price cost stack
Every gallon you buy at the pump breaks down into five named slices. For Idaho today, the stack looks like this:
Crude / refining / distribution shares estimated from EIA Petroleum Marketing Monthly. Federal excise from FHWA Highway Statistics. State excise from the API Motor Fuel Tax Map and Tax Foundation 2026. [EIA · 13 Jul 2026] [API · 13 Jul 2026]
Border-state comparison
For drivers crossing in or out of Idaho, here is how the neighbours print today:
Use the border comparator to compute the per-tank savings of crossing into a cheaper neighbour, and the round-trip mileage at which the detour pays for itself.
Cheapest metro in Idaho
Today's cheapest metro in Idaho is generally Boise. Within-state spread is typically 20-40 cents per gallon depending on county tax overlays, station brand and distance from the wholesale rack. AAA publishes metro-level detail for Idaho updated daily.
FAQ
What is the current average price of regular gas in Idaho?
$4.00 per gallon as of Monday, July 13, 2026, 13 cents above the national average. [AAA · 13 Jul 2026]
What is Idaho's state gas tax?
33.0 cents per gallon state excise, plus the 18.4 cents federal excise. [API · 13 Jul 2026]
Where is gas cheapest in Idaho today?
Boise is typically the cheapest metro. Regional spread is normal at 20-40 cents per gallon.