How Idaho compares
Idaho's diesel rate of $0.3200 is the 26th lowest of the 57 jurisdictions that tax diesel through IFTA this quarter. The average among them is $0.3696; the lowest is Oklahoma at $0.1900 and the highest is California at $0.9790. Idaho does not collect tax on gasoline through IFTA (the matrix lists $0.0000), so gasoline miles there carry no IFTA tax.
Example: 1,000 miles in Idaho
A truck averaging 6.5 MPG that drives 1,000 miles in Idaho burns 153.85 taxable gallons there. If none of its fuel was bought in Idaho, it owes Idaho $49.23 for the quarter (153.85 × $0.3200). Every tax-paid gallon bought in Idaho reduces the base tax by $0.3200. Run your own numbers.
Idaho rates by fuel type, 3rd quarter 2026
| Fuel | U.S. $ per gallon | CAD $ per litre |
|---|---|---|
| Diesel | $0.3200 | $0.1182 |
| Gasoline | $0.0000 | $0.0000 |
| Biodiesel | $0.3200 | $0.1182 |
| Gasohol | $0.0000 | $0.0000 |
| E-85 | $0.0000 | $0.0000 |
Propane, LNG, CNG, electricity and hydrogen are measured in different units from one jurisdiction to the next, so they are not listed here; see the official matrix.
Idaho IFTA rate history
| Quarter | Diesel | Gasoline |
|---|---|---|
| 3Q 2026 | $0.3200 | $0.0000 |
| 2Q 2026 | $0.3200 | $0.0000 |
| 1Q 2026 | $0.3200 | $0.0000 |
| 4Q 2025 | $0.3200 | $0.0000 |
| 3Q 2025 | $0.3200 | $0.0000 |
| 2Q 2025 | $0.3200 | $0.0000 |
| 1Q 2025 | $0.3200 | $0.0000 |
When is the 3rd quarter 2026 return due?
IFTA returns for the 3rd quarter 2026 are due November 2, 2026. You file with your base jurisdiction, which pays Idaho its share; miles in Idaho go on that return whether or not you bought fuel there.
Rather not do this every quarter?
We reconcile your fuel receipts and mileage and prepare the quarterly IFTA return for you, next to your driver files and hours of service.
IFTA rates in other jurisdictions
United States
Canada
Rates in U.S. dollars per gallon (and Canadian dollars per litre) from the final IFTA, Inc. tax rate matrix. IFTAX is not affiliated with IFTA, Inc. or any government agency; confirm rates with your base jurisdiction before filing.