How far is Arnold, MO from O'Fallon, MO?
Fastest route
The distance between Arnold, Missouri and O'Fallon, Missouri is approximately 40.7 miles (65.5 kilometers). The fastest route is via I-270 N and I-70 W, which takes about 41 minutes.
Directions
To get from Arnold to O'Fallon, follow these directions:
- 🚗 Get on I-55 N: Head west on MO-141 N toward Arnold Crossroads Center. Use the right lane to merge onto I-55 N via the ramp to St Louis.
- 🚙 Take I-270 N and I-70 W: Continue on I-55 N and then take I-270 N. Merge onto I-70 W.
- 🚧 Exit at E Terra Ln: Take exit 218 from I-70 W.
- 🛣️ Continue on E Terra Ln: Use the right two lanes to take exit 196 for I-270 W toward Kansas City. Then, take the Kansas City/I-70 E exit toward St Louis. Keep left at the fork and merge onto I-70 W. Take exit 218 toward O'Fallon/Main St.
- 🚦 Drive to S Main St: Continue on E Terra Ln and turn right onto S Main St.
- 📍 Arrive at your destination: Pass by Firestone Complete Auto Care (on the right) to reach your destination.
Tips & Suggestions
- 🚗 Consider using a GPS navigation system or a maps app on your phone to help you navigate the route.
- ⛽ Make sure your vehicle has enough fuel for the journey, especially if you're traveling a long distance.
- 🕑 Check traffic conditions before starting your trip to ensure a smooth and timely journey.
- 🚧 Be aware of any road construction or detours that may affect your route. Stay updated on current road conditions.
- 📱 Keep your mobile phone charged and easily accessible for emergencies or if you need to make a call.
- 🚦 Observe traffic laws and regulations, including speed limits, for a safe and legal journey.
- 🚙 Consider bringing snacks, drinks, and entertainment for a comfortable trip, especially if you're traveling with children.
Reverse, save, or send this route
This is an easy same-day return drive. Copy the route link, send it to another device, or print a clean version before you head out.
This is an easy same-day return drive.
Flight Distance
Driving Distance
Gas Cost Calculator
Leave and Arrive Planner
Pick a departure time to see your estimated arrival and same-day return window.
Drive time stays fixed at 00h 43m.
This is a short drive, so your comfort window is wide. Traffic and current weather matter more than the clock.
You are leaving earlier than the recommended window, which gives you extra margin for breaks and traffic.
Halfway Point
A useful midpoint for breaks, coffee, or meeting in the middle.
Route Weather Snapshot
Check the forecast at both ends before you head out.
Mostly Sunny
Mostly Sunny
Driving Route Map
The map below follows the saved road route between Arnold and O'Fallon.
Turn-by-Turn Driving Directions
Step-by-step road directions between Arnold and O'Fallon.
-
1
Start on Jeffco Boulevard
1.4 km · 2 min · Jeffco Boulevard
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2
Turn left
1283 ft · 28 sec
-
3
Take the ramp slight right toward I 55 North
1225 ft · 30 sec
-
4
Merge slight left onto Police Officer Steven Jarvis Memorial Highway
1.4 km · 1 min · Police Officer Steven Jarvis Memorial Highway
-
5
Continue on Officer Thomas G. Smith, Jr. Memorial Highway
1.9 mi · 2 min · Officer Thomas G. Smith, Jr. Memorial Highway
-
6
Continue on Rosa Parks Highway
1.3 mi · 2 min · Rosa Parks Highway
-
7
Take the exit slight right toward I 270 West, I 255 East: Kansas City, Chicago
1279 ft · 27 sec
-
8
Keep slight left to continue on I 270 West: Kansas City
118 m · 8 sec
-
9
Continue on I 270 West
1.2 km · 1 min
-
10
Merge slight left
18.1 mi · 23 min
-
11
Take the exit slight right toward I 70: Kansas City, Saint Louis, Saint Louis Lambert International Airport
1 mi · 1 min
-
12
Keep slight left to continue on I 70 West: Kansas City
645 ft · 11 sec
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13
Continue on I 70 West: Kansas City
1 km · 57 sec
-
14
Merge slight left
13.6 mi · 17 min
-
15
Take the exit slight right toward MO K: O'Fallon, Main Street
119 m · 8 sec
-
16
Turn straight onto East Terra Lane
1.4 km · 2 min · East Terra Lane
-
17
Turn right onto South Main Street
2830 ft · 1 min · South Main Street
-
18
Turn right
8 m · 2 sec
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19
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between Arnold and O'Fallon.
Highway-focused drive
Most of the mileage stays on named highways, so the important moments are ramps, exits, merges, and the final local approach.
I 270 West
Merge slight left
18.1 mi · 00h 23m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A short regional drive
This route is short enough to handle as a quick errand, commute, or easy same-day return without much planning overhead.
Mostly Sunny leaving Arnold and Mostly Sunny near O'Fallon.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Arnold to O'Fallon?
The road trip is about 41.6 miles (66.9 km) and usually takes 00h 43m in normal driving conditions.
Is this a same-day trip or an overnight route?
This route is short enough to handle as a quick errand, commute, or easy same-day return without much planning overhead.
What is the halfway point on this route?
Creve Coeur is a useful midpoint, sitting about 20.8 miles from Arnold and 20.8 miles from O'Fallon.
How much longer is the road route than the straight-line distance?
The direct path is about 31.4 miles (50.5 km), while the road route adds roughly 10.2 extra miles because roads do not follow the straight air line.
When is the best time to leave for this route?
A good departure window is usually 7:00 AM to 7:00 PM CDT. If you want a more comfortable same-day return, try to leave by 7:02 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $5.54 one way or $11.09 round trip. Estimated CO2 is about 13.1 kg one way.
What should you check before leaving?
Before you leave, expect Mostly Sunny around Arnold and Mostly Sunny near O'Fallon.
Stop Ideas Near Creve Coeur
Useful break, food, and waypoint ideas within about 15 miles of the route midpoint.
Transit and Meeting Points
Useful pickup, handoff, or rendezvous points close to Creve Coeur.
Kirkwood
Gateway Transportation Center
Alton
Washington
Flight Path Map
This map shows the direct air route between Arnold and O'Fallon. Straight-line distance: 31.37 mi (50.48 km).
#1 Arnold
City in Missouri
| Population | 21,145 |
| Coordinates | 38.4328300, -90.3776200 |
| Altitude | 184 |
| Country | United States |
#2 O'Fallon
The most populous city in St.
| Population | 89,769 |
| Coordinates | 38.8106100, -90.6998500 |
| Altitude | 165 |
| Country | United States |
End: (-90.699849, 38.810674)
Estimated Travel Time
Distance: 67 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 23m |
| 40 mph (64.37 km/h) | 01h 02m |
| 50 mph (80.47 km/h) | 00h 49m |
| 60 mph (96.56 km/h) | 00h 41m |
| 70 mph (112.65 km/h) | 00h 35m |
| 80 mph (129 km/h) | 00h 31m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $5.54 | $11.09 |
| Mid-grade | $4.25 | $6.25 | $12.50 |
| Premium | $4.65 | $6.84 | $13.68 |
| Diesel | $5.30 | $7.80 | $15.59 |
Assumes 8.3 L/100 km (about 28.3 MPG). CO2 is an estimate and varies by vehicle, fuel blend, traffic, and terrain.
Prices in Missouri · Apr 23, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.