How far is Mehlville, MO from O'Fallon, MO?
The driving distance from Mehlville, MO to O'Fallon, MO is about 36.8 miles (59.2 km), with a travel time of about 00h 38m by car.
- The straight-line flight distance is about 29.1 miles (46.9 km).
- For a round trip, plan for roughly 01h 17m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 7:00 AM to 7:00 PM CDT.
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 38m.
This is a short drive, so your comfort window is wide. Traffic and current weather matter more than the clock.
This departure sits inside the recommended comfort window for the route.
Halfway Point
A useful midpoint for breaks, coffee, or meeting in the middle.
City in Missouri, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Slight Chance Rain Showers
Partly Cloudy
Driving Route Map
The map below follows the saved road route between Mehlville and O'Fallon.
Turn-by-Turn Driving Directions
Step-by-step road directions between Mehlville and O'Fallon.
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1
Start on Lemay Ferry Road
2211 ft · 56 sec · Lemay Ferry Road
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2
Take the ramp left toward I 270 West
895 ft · 33 sec
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3
Merge slight left
3093 ft · 44 sec
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4
Continue straight
18.7 mi · 23 min
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5
Take the exit slight right toward I 70: Kansas City, Saint Louis, Saint Louis Lambert International Airport
1 mi · 1 min
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6
Keep slight left to continue on I 70 West: Kansas City
645 ft · 11 sec
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7
Continue on I 70 West: Kansas City
1 km · 57 sec
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8
Merge slight left
13.6 mi · 17 min
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9
Take the exit slight right toward MO K: O'Fallon, Main Street
119 m · 8 sec
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10
Turn straight onto East Terra Lane
1.4 km · 2 min · East Terra Lane
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11
Turn right onto South Main Street
2830 ft · 1 min · South Main Street
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12
Turn right
8 m · 2 sec
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13
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between Mehlville 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
Continue straight
18.7 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.
Slight Chance Rain Showers leaving Mehlville and Partly Cloudy near O'Fallon.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Mehlville to O'Fallon?
The road trip is about 36.8 miles (59.2 km) and usually takes 00h 38m 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?
Maryland Heights is a useful midpoint, sitting about 18.4 miles from Mehlville and 18.4 miles from O'Fallon.
How much longer is the road route than the straight-line distance?
The direct path is about 29.1 miles (46.9 km), while the road route adds roughly 7.7 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 7:12 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $4.90 one way or $9.80 round trip. Estimated CO2 is about 11.6 kg one way.
What should you check before leaving?
Before you leave, expect Slight Chance Rain Showers around Mehlville and Partly Cloudy near O'Fallon.
Stop Ideas Near Maryland Heights
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 Maryland Heights.
Kirkwood
Gateway Transportation Center
Alton
Washington
Flight Path Map
This map shows the direct air route between Mehlville and O'Fallon. Straight-line distance: 29.15 mi (46.91 km).
#1 Mehlville
Census designated place
| Population | 28,380 |
| Coordinates | 38.5083900, -90.3228900 |
| 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: 59 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 13m |
| 40 mph (64.37 km/h) | 00h 55m |
| 50 mph (80.47 km/h) | 00h 44m |
| 60 mph (96.56 km/h) | 00h 36m |
| 70 mph (112.65 km/h) | 00h 31m |
| 80 mph (129 km/h) | 00h 27m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $4.90 | $9.80 |
| Mid-grade | $4.25 | $5.53 | $11.06 |
| Premium | $4.65 | $6.05 | $12.10 |
| Diesel | $5.30 | $6.90 | $13.79 |
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 29, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.