Idaho Gas Tax Calculator
2026Idaho charges 33¢ a gallon in state tax on gasoline and 33¢ on diesel in 2026, on top of the federal 18.4¢ and 24.4¢: 51.4¢ and 57.4¢ a gallon in all. Estimate your fuel costs.
By Konstantin Iakovlev · Updated October 19, 2026 · Methodology
Fuel Needed
1.0 gal
Trip Cost
$4.33
Annual Cost
$1,125.80
Fuel Cost Breakdown
| Total Distance | 30.0 miles |
| Fuel Needed | 1.00 gallons |
| One-Way Cost | $4.33 |
| Trip Cost | $4.33 |
| Weekly Cost | $21.65 |
| Monthly Cost | $93.82 |
| Annual Cost | $1,125.80 |
Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.
Idaho Gas Tax Overview
Idaho’s state tax on gasoline is 33¢ a gallon and 33¢ on diesel, the rate in force since July 1, 2015. That is the 21st-highest state gasoline tax of the 50 states and DC. Fixed by statute; the 1¢ fee pauses when its trust fund reaches $35 million and resumes at $25 million.
With the federal 18.4¢, a gallon of gasoline carries 51.4¢ of per-gallon tax, so a 15-gallon fill-up includes about $7.71 of fuel tax whatever the pump price.
Idaho Fuel Taxes (2026)
| State Gasoline Tax | 33¢/gal |
| State Diesel Tax | 33¢/gal |
| Federal Excise Tax | 18.4¢ gasoline / 24.4¢ diesel |
| Total per Gallon | 51.4¢ gasoline / 57.4¢ diesel |
| How the State Rate Is Built | Gasoline and diesel: 32¢ fuel tax + 1¢ petroleum transfer fee for the clean water trust fund. |
Official Sources: