Fuel cost calculator · About 295 miles
Gas cost from Chicago to St. Louis
The drive from Chicago, IL to St. Louis, MO is about 295 miles, so a round trip costs about $83.62 in gas at this week's average of $4.25 a gallon. Change the car, fuel or distance below for your own figure.
What the trip costs by vehicle
| Vehicle | One way | Round trip |
|---|---|---|
| Compact car (33 mpg) | $38.01 | $76.01 |
| Midsize sedan (30 mpg) | $41.81 | $83.62 |
| Hybrid (50 mpg) | $25.08 | $50.17 |
| Minivan (22 mpg) | $57.01 | $114.02 |
| SUV (24 mpg) | $52.26 | $104.52 |
| Pickup truck (19 mpg) | $66.01 | $132.02 |
Regular gas at $4.252 a gallon, the average of this week's Illinois and Missouri prices, from the EIA’s weekly survey. Fuel only: tolls and parking are not included.
Fuel economy figures are round examples for each kind of vehicle, not official ratings. Your own car's EPA rating is on fueleconomy.gov.
Distance: fastest route between city centres, rounded to the nearest 5 miles, calculated with OSRM on OpenStreetMap road data (© OpenStreetMap contributors), measured November 2026.
295 miles in Illinois
$41.79
9.8 gallons at $4.25 a gallon
$0.95 more than the same trip at the national average.
- Per mile
- 14.2¢
- A full tank
- $63.75
- about 450 miles
- A year of driving
- $1,700
- $142 a month
Where to fill up
Regular is about $0.42 a gallon cheaper in Missouri than in Illinois this week, $6.26 on a 15-gallon fill. Fill the tank on the Missouri side of the trip. See how Missouri’s gas tax compares.
Chicago to St. Louis by car
- How much does gas cost from Chicago to St. Louis?
- About $41.81 one way, or $83.62 for the round trip, in a car that gets 30 mpg. That assumes 295 miles and this week's average regular price of $4.25 a gallon. An SUV at 24 mpg spends about $52.26 one way; a hybrid at 50 mpg about $25.08.
- How far is Chicago from St. Louis by car?
- About 295 miles on the fastest route between the two city centres, measured on OpenStreetMap road data. Your own start and end points may make it a little longer or shorter; type your distance into the calculator for an exact figure.
- How many gallons of gas does the drive take?
- About 9.8 gallons one way at 30 mpg. That fits in a typical 15-gallon tank, so most cars can make it without stopping for fuel.
- Is gas cheaper in Illinois or Missouri?
- This week regular is about $0.42 a gallon cheaper in Missouri, which is $6.26 on a 15-gallon fill. About 42¢ of that gap is state fuel tax. Filling up before you leave Missouri saves the most.