How far is Eureka, MO from O'Fallon, MO?
Distance by Flight
Shortest distance between Eureka and O'Fallon is 21.64 miles (34.82 km).
Flight distance from Eureka, MO to O'Fallon, MO is 21.64 miles. Estimated flight time is 00 hours 03 minutes.
Driving distance
The driving distance from Eureka, Missouri to O'Fallon, Missouri is: 26.14 miles (42.07 km) by car.
Driving from Eureka to O'Fallon will take approximately 00 hours 42 minutes.
#1 Eureka
| Population | |
|---|---|
| GPS Coordinates | 38°30'9"N 90°37'40"W |
| Latitude | 38.5025500 |
| Longitude | -90.6279000 |
| Altitude | 139 |
| Country | United States |
#2 O'Fallon
The most populous city in St. Charles County, Missouri. It is located in the eastern part of the county. O'Fallon is known for its many parks and green spaces, its many historical sites, and its many attractions, such as the O'Fallon City Hall and the O'Fallon History Museum.
| Population | 89769 |
|---|---|
| GPS Coordinates | 38°48'38"N 90°41'59"W |
| Latitude | 38.8106100 |
| Longitude | -90.6998500 |
| Altitude | 165 |
| Country | United States |
Ending point in O'Fallon: (-90.699849,38.810674)
Estimated Travel Time Between Eureka and O'Fallon
The distance between Eureka and O'Fallon is 42 km if you choose to drive by road. You can go 00 hours 28 minutes if you drive your car at an average speed of 90 kilometers / hour. For different choices, please review the avg. speed travel time table on the below.
There is no time difference between Eureka and O'Fallon. The current time is 17:15:54.
| Average Speed | Travel Time |
|---|---|
| 30 mph (48.3 km/h) | 00 hours 52 minutes |
| 40 mph (64.37 km/h) | 00 hours 39 minutes |
| 50 mph (80.47 km/h) | 00 hours 31 minutes |
| 60 mph (96.56 km/h) | 00 hours 26 minutes |
| 70 mph (112.65 km/h) | 00 hours 22 minutes |
| 75 mph (120.7 km/h) | 00 hours 20 minutes |
| 80 mph (128.75 km/h) | 00 hours 19 minutes |
Gas Consumption
A car with a fuel efficiency of 8.3 l/100 km will need 3.49 liters (0.92 gallon) of gas to cover the route between Eureka and O'Fallon.
The estimated cost of gas to go from Eureka to O'Fallon is $2.96 (diesel $4.08).
Missouri gas prices.
| Gasoline | Mid Grade | Premium | Diesel | |
|---|---|---|---|---|
| Gallon | $3.21 | $3.54 | $3.86 | $4.43 |
| Total | $2.96 | $3.26 | $3.56 | $4.08 |
Take a look at our Gas Cost Calculator feature. It will figure out how much it will cost to drive this particular distance.
The average gas price (in Missouri ) per gallon of daily gas for calculations is $3.205 (Diesel $4.426) /gallon. Last changed prices on December 29, 2025.
How did we calculate the distance?
The place names are translated into coordinates to approximate the distance between Eureka and O'Fallon (latitude and longitude). Cities, states, and countries each have their own regional center. The Haversine formula is used to measure the radius.
Distance to Other Cities
Driving distance from New York, MO to Eureka 245.5 miles (395 km)
Driving distance from Castle Point, MO to Eureka 40.63 miles (65 km)
Driving distance from East Independence, MO to Eureka 229.07 miles (369 km)
