Illinois Gas Tax Calculator
2026Calculate total gas tax per gallon in Illinois, including the federal excise tax of $0.184/gal and IL state fuel taxes. Compare Illinois gas and diesel tax rates for 2026.
Written and reviewed by Konstantin Iakovlev · Methodology · Updated
Fuel Needed
1.0 gal
Trip Cost
$4.10
Annual Cost
$1,066.00
Fuel Cost Breakdown
| Total Distance | 30.0 miles |
| Fuel Needed | 1.00 gallons |
| One-Way Cost | $4.10 |
| Trip Cost | $4.10 |
| Weekly Cost | $20.50 |
| Monthly Cost | $88.77 |
| Annual Cost | $1,066.00 |
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.
How much is gas tax in Illinois?
Every gallon of gasoline pumped in Illinois carries two layers of tax: a federal excise tax of 18.4¢ per gallon (24.4¢ for diesel) collected by the IRS, and a state-level fuel tax of approximately 39.2¢ per gallon that funds Illinois highway, bridge, and transit projects. Combined, that's roughly 57.6¢ per gallon in 2026.
State gas tax rates vary widely — from under 10¢/gal in Alaska to nearly 60¢/gal in California and Pennsylvania. Some states, including Illinois, periodically adjust the rate via fuel-index formulas tied to wholesale prices or inflation, so the figure can drift mid-year. Many states also stack on smaller environmental, underground-storage-tank, or pre-paid sales-tax fees that aren't always shown at the pump but are baked into the posted price.
For a typical 12-gallon fillup in Illinois, you contribute about $6.91 to combined road and federal infrastructure funds before any sales tax. Use the calculator above with your local pump price and tank capacity for an exact breakdown of pre-tax fuel cost vs. tax burden.
Illinois fuel-tax history, indexing, and where the money goes
- Diesel state tax (2026)
- 47¢ per gallon
- Last increase
- 2024 (annual CPI adjustment under Rebuild Illinois 2019)
- Indexed?
- Yes — adjusts automatically
- Where revenue goes
- Road Fund (constitutionally protected by 2016 lockbox amendment)
Illinois doubled its gas tax from 19¢ to 38¢ in 2019 under the $45B "Rebuild Illinois" capital plan, and the rate is now indexed annually to CPI — reaching ~39.2¢ in 2026 (the second-highest in the Midwest after Pennsylvania). The 2016 "lockbox" constitutional amendment prohibits diversion of road-fund revenue. Chicago and Cook County add separate gas taxes, pushing the city's all-in rate above 70¢/gal — among the highest in the country. Illinois added a $100 EV surcharge in 2020.
Illinois Tax Rates (2026)
| Federal Gas Tax | $0.184/gal |
| State Sales Tax | 6.25% |
| State Income Tax | 4.95% (flat) |
| Avg. Property Tax Rate | 2.07% |
Gas tax — frequently asked questions
What is the total Illinois gas tax in 2026?
Illinois's 2026 state gasoline excise tax is approximately 49.4¢/gallon — second-highest in the Midwest after Pennsylvania. Diesel is 47.0¢/gallon. The state doubled the rate from 19¢ to 38¢ in 2019 under the $45B Rebuild Illinois capital plan, and it now indexes annually to CPI. Chicago and Cook County add separate local gas taxes that push the city's all-in pump rate above 70¢/gallon — among the highest in the country.
When did Illinois double its gas tax?
Illinois doubled its gas tax from 19¢ to 38¢ on July 1, 2019 under the Rebuild Illinois capital plan signed by Governor Pritzker. The reform also added annual CPI indexing — the rate has risen every July since, reaching about 49.4¢ for 2026. The 2016 lockbox constitutional amendment prohibits diversion of road-fund revenue to other purposes. Illinois added a $100 EV registration surcharge in 2020.
Why is Chicago's gas tax higher than the rest of Illinois?
Chicago drivers pay the state's 49.4¢ excise plus a Cook County Motor Fuel Tax of 6¢/gallon and a Chicago Motor Fuel Tax of 8¢/gallon, plus the City of Chicago and Cook County Use Tax components on top of state and federal sales tax — pushing the all-in pump rate above 70¢/gallon. Local revenue funds the Chicago Department of Transportation and Cook County highways. The pump price differential between Chicago and downstate Illinois often exceeds 30¢/gallon.