Illinois is a strange case when it comes to gas prices. It sits right in the middle of the country, close to plenty of refineries, surrounded by states with cheap gas — and yet Illinois drivers pay some of the highest prices in the entire Midwest. Right now, in June 2026, the average price for regular gas in Illinois is about $4.12 per gallon. Drive across the border into Indiana or Missouri and you'll often pay 40 to 60 cents less for the exact same gallon. So what's the deal? Why is Illinois so much more expensive than its neighbors?
Illinois average: $4.12/gallon · National average: $4.44/gallon · Midwest neighbors like Indiana and Missouri: around $3.00-3.12/gallon · Source: EIA.gov
The short answer is taxes. Illinois has built up one of the heaviest gas tax loads in the country, and if you live in Chicago, it gets even worse. Let me walk you through exactly what's happening.
The Real Reason: Illinois Loves Gas Taxes
The State Gas Tax Is Huge
Illinois charges around 47 cents per gallon in state gas tax — and that number keeps climbing because the state tied it to inflation back in 2019. Every July, the tax goes up automatically. Most states have a fixed gas tax that stays the same for years. Illinois built in a yearly increase, so the gap between Illinois and cheaper states keeps getting wider over time.
Then There's the Sales Tax on Gas
Here's something a lot of states don't do — Illinois charges regular sales tax on top of the gas tax. So you're paying tax on the fuel, and then more tax on the total. It stacks up. Most low-tax states like Texas don't pile sales tax onto gasoline the way Illinois does.
Chicago and Cook County Pile On More
If you live in Chicago, brace yourself. The city of Chicago adds its own gas tax, and Cook County adds another one on top of that. So a Chicago driver is paying the state tax, the state sales tax, the county tax, AND the city tax — four layers of taxes on one gallon of gas. This is exactly why gas in Chicago is so much more expensive than the rest of Illinois.
Gas Prices Around Illinois — City by City
Where you fill up in Illinois makes a real difference. Here's what prices look like in June 2026:
Look at that gap — gas in Springfield is about 49 cents cheaper than in Chicago. Same state, same week, but the Chicago and Cook County taxes make a massive difference. If you're driving through Illinois, fill up in the central or southern part of the state and skip the Chicago area entirely if you can.
Why Indiana Drivers Have It Easy (And Illinois People Drive There)
One thing you'll notice if you live near the Illinois-Indiana border: a lot of people cross over to fill up. It's not your imagination. Indiana's gas taxes are lower, so gas there often runs 30 to 60 cents cheaper per gallon. For folks in the south Chicago suburbs, a quick trip across the state line can save real money on a full tank. Some people plan their fill-ups around it.
How Illinois Stacks Up Against Other States
| State | Regular Price | vs Illinois |
|---|---|---|
| California | $5.97 | +$1.85 |
| National Average | $4.44 | +$0.32 |
| Illinois | $4.12 | — |
| Ohio | $3.19 | -$0.93 |
| Indiana | $3.12 | -$1.00 |
| Missouri | $3.02 | -$1.10 |
This table really tells the story. Illinois is surrounded by Midwest states paying around $3.00-3.20, while Illinois drivers pay $4.12. That dollar-per-gallon difference isn't because of oil or refineries — it's almost entirely taxes. Missouri sits right across the river from Illinois and pays $1.10 less per gallon.
How to Pay Less for Gas in Illinois
You can't vote away the gas tax today, but here's what actually works:
- Stay out of Chicago and Cook County for fill-ups. This is the single biggest thing. The suburbs outside Cook County are cheaper, and central Illinois is cheaper still.
- Cross into Indiana or Missouri if you're close. If you live near a border, it's worth it. Plenty of Illinois folks already do this.
- Use GasBuddy. In a big metro like Chicago, prices swing a lot from station to station. The app finds the cheapest one near you.
- Hit the warehouse clubs. Costco, Sam's Club, and BJ's all have locations around Illinois with prices well below the corner station.
- Fill up before July. Remember, the Illinois gas tax goes up every July 1st. If you can time a big trip's fill-up before then, you dodge the latest increase for a bit.
If you live in Chicago, even driving to the suburbs just outside Cook County can save you 25 to 40 cents a gallon. On a 15-gallon tank, that's $4 to $6 per fill-up — and over a year of weekly fill-ups, that adds up to a few hundred dollars staying in your pocket.
Frequently Asked Questions
The Bottom Line
Illinois gas is expensive for one main reason: taxes, layered on top of each other, with Chicago and Cook County making it worse. It's frustrating because the state isn't far from refineries and shouldn't naturally be this pricey. But until the tax situation changes, your best move is simple — fill up outside Cook County, cross into Indiana or Missouri when you can, and use an app to find the cheapest station. Those small habits add up to real savings over a year.
Want to keep track of current prices? Our live gas price tracker updates every Monday with the latest Illinois numbers and all 50 states, pulled straight from EIA.gov.