Illinois Gas Prices
Average retail price · Source: AAA · Updated daily
Today's Average
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per gallon · regular unleaded
Illinois ranks among the most expensive states for gas due to its 66¢/gallon state tax — second only to California — combined with Cook County and Chicago city taxes that can add another 20¢+ in the metro area. Downstate Illinois sees significantly lower prices once you escape the Chicago tax burden.
⛽ Gas Tax: 66¢/gallon
Ranked #3 most expensive nationally
Top Gas Station Chains in Illinois
BPShellCasey'sThorntonsSpeedway
Top Illinois Cities for Gas Prices
Illinois Gas Price FAQ
Why is gas so expensive in Chicago?
Chicago drivers pay the state tax (66¢/gallon) plus Cook County and City of Chicago taxes that can add 20-25¢ more. The total tax burden in Chicago is among the highest of any major US city, often exceeding even California metro areas.
How much cheaper is gas outside Chicago?
Drivers can save 40-70¢ per gallon by filling up in suburban Cook County or collar counties vs. Chicago proper. Crossing into Indiana from the Chicago Southland can save even more — Indiana's gas tax is about 40¢/gallon less than Illinois.
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Gas Prices by City in Illinois
Illinois Gas Price — Frequently Asked Questions
What is the average gas price in Illinois today?
Illinois gas prices are updated daily from AAA data. Check back for today's average.
Why are gas prices lower in Illinois than the national average?
Illinois prices are driven by high state and local taxes (~46¢/gal), particularly in the Chicago metro area where additional county taxes apply.
What is Illinois's gas tax?
Illinois's state gas tax is approximately 46¢ per gallon. This is a combined state excise tax and in some states includes local levies. The federal gas tax adds an additional 18.4¢/gal on top of state taxes.
When is the cheapest time to buy gas in Illinois?
Gas prices in Illinois — like across the US — tend to be lowest on Mondays and Tuesdays, when weekly demand is lowest. Prices typically rise Thursday through Saturday as weekend travel demand increases. Avoiding fill-ups on Fridays and Saturdays can save 3–8¢/gal on average. Illinois prices also tend to be lower in late fall and winter when summer-blend fuel requirements end.
Which cities in Illinois have the cheapest gas?
Gas prices vary by city within Illinois based on local competition, distance from fuel terminals, and population density. Use our city pages to compare prices across Illinois: cities farther from major metro areas and distribution hubs often have slightly higher prices due to transport costs, while high-competition suburban areas near major highways tend to be cheapest.