Gas prices in Illinois today
Regular gas in Illinois averages $4.90 a gallon, 15% more than the U.S. average of $4.27. That makes Illinois one of the most expensive: rank 47 of 51 (1 = cheapest).
| Grade | Illinois | U.S. average | 15-gallon fill-up |
|---|---|---|---|
| Regular | $4.90 | $4.27 | $73 |
| Mid-grade | $5.49 | $4.78 | $82 |
| Premium | $6.04 | $5.17 | $91 |
| Diesel | $6.68 | $6.35 | $100 |
Source: AAA, Illinois average gas prices and AAA State Gas Price Averages, as of Oct 24, 2026. Fill-up = price × 15 gallons (our calculation). For metro-area prices, see AAA's Illinois page.
Taxes in the price: 70.4¢ a gallon in Illinois state taxes and fees plus the 18.4¢ federal tax, 88.8¢ in all, about 18% of today's price (Tax Foundation, July 2026; our calculation). Gas tax in Illinois.
What driving costs in Illinois
At $4.90 a gallon, a car that gets 27.2 mpg (the EPA's average for new vehicles) spends about $180 on gas every 1,000 miles, or 18.0 cents a mile (our calculation). Charging an electric car at Illinois's average home electricity price costs about $60 for the same 1,000 miles. Gas is only one part of the bill: full-coverage car insurance in Illinois averages $1,944 a year.
Planning a drive? The road trip cost calculator uses today's gas price, and the true cost of owning a car puts fuel next to insurance, repairs and depreciation.
Common questions
What is the average gas price in Illinois today?
Regular gas in Illinois averaged $4.90 a gallon on Oct 24, 2026, per AAA. Mid-grade was $5.49, premium $6.04 and diesel $6.68.
Is gas in Illinois cheaper than the national average?
No. Illinois's $4.90 is 15% more than the U.S. average of $4.27, which ranks it 47 of 51 states and DC (1 = cheapest, our ranking of AAA data).
How much does it cost to fill up a car in Illinois?
About $73 for 15 gallons of regular at today's Illinois average (our calculation). Driving 1,000 miles in a car that gets 27.2 mpg costs about $180 in gas.
Is an electric car cheaper to run than gas in Illinois?
At Illinois's average home electricity price, charging an EV for 1,000 miles costs about $60, compared with about $180 in gas for a 27.2 mpg car (our calculation from EIA and AAA prices, 31 kWh per 100 miles from fueleconomy.gov).
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