Diesel Prices in Idaho Today
Average diesel price in Idaho: $6.590 per gallon on September 22, 2026. U.S. average $6.529. Updated daily.
What is the price of diesel in Idaho today?
Diesel in Idaho averages $6.590 per gallon today (September 22, 2026), $0.061 more than the U.S. average of $6.529. Idaho ranks #39 of 51 for cheapest diesel (1 = cheapest). A loaded semi at about 6.3 mpg spends about $1.05 per mile on fuel in Idaho.
per gallon today
U.S. average $6.529
of 51 (1 = cheapest)
semi truck, today
Fuel cost per mile in Idaho
Estimated diesel cost at today's Idaho price of $6.590 a gallon, using fuel economy calibrated to FHWA and NACFE data.
| Truck | Fuel per mile | Fuel per 1,000 miles |
|---|---|---|
| Dry Van38,000 lbs, ~6.3 mpg | $1.05 | $1,048 |
| Reefer38,000 lbs, ~6.0 mpg | $1.09 | $1,091 |
| Flatbed40,000 lbs, ~6.0 mpg | $1.09 | $1,090 |
| Hotshot12,000 lbs, ~8.9 mpg | $0.74 | $740 |
| Box Truck7,000 lbs, ~9.1 mpg | $0.72 | $722 |
Your numbers depend on load weight, speed, terrain and idling. Enter them in the truck fuel cost calculator for an exact estimate.
Frequently asked questions
What is the price of diesel in Idaho today?
Diesel in Idaho averages $6.590 per gallon today (September 22, 2026), $0.061 more than the U.S. average of $6.529. Idaho ranks #39 of 51 for cheapest diesel (1 = cheapest). A loaded semi at about 6.3 mpg spends about $1.05 per mile on fuel in Idaho.
How much does it cost to fill a semi truck in Idaho?
At $6.59 a gallon, 150 gallons of diesel costs about $988 and 200 gallons about $1,318 in Idaho today.
Is diesel cheaper in Idaho than nearby states?
Among nearby states in the same region, the cheapest today is Wyoming at $6.215 a gallon. Idaho is $6.590.
How often are Idaho diesel prices updated?
Every day. This page refreshes each morning from daily state averages, with the EIA weekly survey as a backup.
| Wyoming | $6.215 |
| Colorado | $6.220 |
| Montana | $6.313 |
| Utah | $6.564 |
Source: AAA daily state average, September 22, 2026. All 50 states
Running freight through Idaho?
Texas Solutions dispatches semis for 5%, hotshots for 8% and box trucks for 10% of weekly gross. We plan lanes to cut empty miles and fuel.