Midwest region
IllinoisGas prices
EIA doesn’t publish a weekly price for Illinois on its own. This figure starts from the Midwest average of $4.109 for the week of October 5, 2026 and adjusts it for Illinois’s fuel tax, which is 35.8¢ a gallon above the regional norm. How we estimate it.
Midwest prices this week
The regional averages Illinois’s figures are drawn from, in dollars per gallon.
- Regular
- $4.109
- Down $0.182 on the week
- Midgrade
- $4.562
- Down $0.194 on the week
- Premium
- $5.230
- Down $0.176 on the week
- Diesel
- $6.286
- Down $0.240 on the week
The regional price is toward the high end of its past-year range: over the past 52 weeks it has run from $2.585 to $4.405, averaging $3.437. It has moved +5.5% over four weeks and +16.4% over thirteen.
How much of a gallon is tax
Illinois charges 71.7¢ a gallon in state tax, the 2nd highest of 51 (the 50 states and D.C.). With the federal tax that is 90.1¢, about 20% of the pump price.
| State excise tax | 49.60¢ |
|---|---|
| Other state taxes and fees | 22.10¢ |
| Federal excise tax | 18.40¢ |
| Total per gallon | 90.10¢ |
| On a 15-gallon fill | $13.52 |
| Over a year of typical driving | $432 |
From EIA’s notes for Illinois: Prepaid Sales Tax Rates: $0.
Source: EIA federal and state motor fuel taxes, July 2026. A typical year assumes 480 gallons (about 12,000 miles at 25 mpg). Local sales taxes are not included.
Fuel tax in Illinois and its neighbours
Across the line in Kentucky, state tax is 45.3¢ a gallon lower, which is $6.80 less tax on a 15-gallon fill.
| State | State tax | Versus IL | On a 15-gal tank |
|---|---|---|---|
| Kentucky | 26.4¢ | −45.3¢ | −$6.80 |
| Missouri | 30.0¢ | −41.7¢ | −$6.26 |
| Iowa | 30.0¢ | −41.7¢ | −$6.25 |
| Wisconsin | 32.9¢ | −38.8¢ | −$5.82 |
| Indiana | 64.5¢ | −7.2¢ | −$1.08 |
| Illinois | 71.7¢ | — | — |
What driving in Illinois costs
- A 15-gallon fill
- $67.01
- A year of typical driving
- $2,144
- Versus the national average
- $54 a year more
Planning a drive? The fuel cost calculator prices a trip at this week’s Illinois figure, for your own car.
How we estimate the Illinois price
The U.S. Energy Information Administration surveys retail gasoline prices every Monday, but it reports individual figures for only nine states. Illinois is counted in the Midwest series, which averages it together with Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee and Wisconsin.
Within one region, crude oil, refining and most delivery costs are shared. The biggest fixed difference from one state to the next is tax, which reaches the pump almost cent for cent. So we take the regional average and add the gap between Illinois’s tax (71.7¢) and the average tax across the region’s states (35.9¢).
Local taxes, how busy the local market is and how far the state is from a refinery all move real prices too, so treat this as a guide to within a few cents, not a quote. Our methodology covers how every figure on the site is sourced.
Gas prices in Illinois
- How much is gas in Illinois right now?
- Regular gasoline in Illinois is estimated at about $4.47 a gallon this week. That starts from the EIA's Midwest average of $4.109 and adjusts it for Illinois's fuel tax, which is 35.8¢ a gallon above the average across the region's states. The national average is $4.354.
- How much is the gas tax in Illinois?
- Illinois charges 49.60¢ a gallon in state excise tax plus 22.10¢ in other per-gallon taxes and fees, 71.70¢ in all. That ranks 2 of 51 (the 50 states and D.C.), highest first. With the 18.4¢ federal tax, a gallon carries 90.1¢ of tax.
- Is gas cheaper in a state next to Illinois?
- On tax alone, yes. Kentucky has the lowest fuel tax of Illinois's neighbours at 26.4¢ a gallon, 45.3¢ less than Illinois. On a 15-gallon fill that is $6.80 less tax. Station prices vary, so the saving at any one pump can be larger or smaller.
- Why is there no official weekly gas price for Illinois?
- The EIA's weekly survey samples about 1,000 stations nationwide, enough for reliable regional averages and for nine large states, but not for every state on its own. Illinois is counted in the Midwest series, which is updated every Monday and published on Tuesday.