How far is O'Fallon, MO from Affton, MO?
The driving distance from O'Fallon, MO to Affton, MO is about 35.9 miles (57.7 km), with a travel time of about 00h 49m by car.
- The straight-line flight distance is about 26.7 miles (43 km).
- For a round trip, plan for roughly 01h 39m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 8:00 AM to 10:00 AM CDT.
Reverse, save, or send this route
This route works well as a day trip with time at the destination. Copy the route link, send it to another device, or print a clean version before you head out.
This route works well as a day trip with time at the destination.
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 49m.
A morning start gives you useful time at the destination and keeps the return out of the late evening.
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.
City in Missouri, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Chance Showers And Thunderstorms then Showers And Thunderstorms Likely
Partly Sunny then Chance Showers And Thunderstorms
Driving Route Map
The map below follows the saved road route between O'Fallon and Affton.
Turn-by-Turn Driving Directions
Step-by-step road directions between O'Fallon and Affton.
-
1
Start on the route
8 m · 7 sec
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2
Turn left onto South Main Street
3116 ft · 2 min · South Main Street
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3
Turn left onto Drennen Parkway
1.4 km · 1 min · Drennen Parkway
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4
Take the ramp slight left toward I 70 East: Saint Louis
133 m · 6 sec
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5
Merge slight left
13.5 mi · 17 min
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6
Take the exit slight right toward I 270: Chicago, Memphis
872 ft · 12 sec
-
7
Keep slight right to continue on I 270 South: Memphis
2339 ft · 33 sec
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8
Continue on I 270 South: Memphis
723 ft · 10 sec
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9
Merge slight left
15.6 mi · 19 min
-
10
Take the exit slight right toward MO 30: Gravois Road
1580 ft · 34 sec
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11
Keep slight left to continue on MO 30: Saint Louis, Ulysses S. Grant National Historic Site, Gravois Road
121 m · 11 sec
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12
Merge slight right
4.1 mi · 8 min
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13
Turn right
12 m · 8 sec
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14
Turn left
27 m · 6 sec
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15
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between O'Fallon and Affton.
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 South
Merge slight left
15.6 mi · 00h 19m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A comfortable day-trip route
This route works well as a day trip. You can leave in the morning, spend meaningful time at the destination, and still return the same day.
Chance Showers And Thunderstorms then Showers And Thunderstorms Likely leaving O'Fallon and Partly Sunny then Chance Showers And Thunderstorms near Affton.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from O'Fallon to Affton?
The road trip is about 35.9 miles (57.7 km) and usually takes 00h 49m in normal driving conditions.
Is this a same-day trip or an overnight route?
This route works well as a day trip. You can leave in the morning, spend meaningful time at the destination, and still return the same day.
What is the halfway point on this route?
Maryland Heights is a useful midpoint, sitting about 17.9 miles from O'Fallon and 18 miles from Affton.
How much longer is the road route than the straight-line distance?
The direct path is about 26.7 miles (43 km), while the road route adds roughly 9.2 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 8:00 AM to 10:00 AM CDT. If you want a more comfortable same-day return, try to leave by 4:50 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $4.79 one way or $9.58 round trip. Estimated CO2 is about 11.3 kg one way.
What should you check before leaving?
Before you leave, expect Chance Showers And Thunderstorms then Showers And Thunderstorms Likely around O'Fallon and Partly Sunny then Chance Showers And Thunderstorms near Affton.
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 O'Fallon and Affton. Straight-line distance: 26.72 mi (43 km).
#1 O'Fallon
The most populous city in St.
| Population | 89,769 |
| Coordinates | 38.8106100, -90.6998500 |
| Altitude | 165 |
| Country | United States |
#2 Affton
Census designated place
| Population | 20,307 |
| Coordinates | 38.5506100, -90.3331700 |
| Altitude | 188 |
| Country | United States |
End: Affton (-90.33317, 38.55061)
Estimated Travel Time
Distance: 58 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 11m |
| 40 mph (64.37 km/h) | 00h 53m |
| 50 mph (80.47 km/h) | 00h 43m |
| 60 mph (96.56 km/h) | 00h 35m |
| 70 mph (112.65 km/h) | 00h 30m |
| 80 mph (129 km/h) | 00h 26m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $4.79 | $9.58 |
| Mid-grade | $4.25 | $5.40 | $10.80 |
| Premium | $4.65 | $5.91 | $11.82 |
| Diesel | $5.30 | $6.74 | $13.47 |
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 15, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.