How far is O'Fallon, MO from Marshfield, MO?
The driving distance from O'Fallon, MO to Marshfield, MO is about 185.8 miles (299 km), with a travel time of about 03h 40m by car.
- The straight-line flight distance is about 157.3 miles (253.2 km).
- For a round trip, plan for roughly 07h 21m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 6:00 AM to 8:00 AM CDT.
Reverse, save, or send this route
This drive is better planned with a longer stop or an overnight stay. Copy the route link, send it to another device, or print a clean version before you head out.
This drive is better planned with a longer stop or an overnight stay.
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 03h 40m.
An early departure helps you fit a real stop into the day without turning the return into a late-night drive.
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 Phelps County, Missouri, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Partly Sunny then Slight Chance Rain Showers
Chance Showers And Thunderstorms
Driving Route Map
The map below follows the saved road route between O'Fallon and Marshfield.
Turn-by-Turn Driving Directions
Step-by-step road directions between O'Fallon and Marshfield.
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1
Start on the route
8 m · 7 sec
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2
Turn left onto South Main Street
2865 ft · 1 min · South Main Street
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3
Continue straight
3.1 mi · 6 min
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4
Continue straight
3.4 mi · 5 min
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5
Take the ramp slight right toward I 64 East, US 40 East, US 61 South
1523 ft · 22 sec
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6
Merge slight left onto Avenue of the Saints
3.7 mi · 5 min · Avenue of the Saints
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7
Take the exit slight right toward Chesterfield Airport Road
2700 ft · 58 sec
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8
Continue on Chesterfield Airport Road
110 m · 7 sec · Chesterfield Airport Road
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9
Turn right onto Olive Street Road
64 m · 5 sec
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10
Turn right onto Olive Street Road
1.5 km · 2 min · Olive Street Road
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11
Continue on North Eatherton Road
2.4 mi · 5 min · North Eatherton Road
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12
Enter the roundabout and take exit 2 toward the route
21 m · 1 sec
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13
Exit the roundabout
4.3 mi · 7 min
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14
Enter the roundabout and take exit 2 toward the route
29 m · 2 sec
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15
Exit the roundabout
2098 ft · 45 sec
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16
Enter the roundabout and take exit 2 toward MO 100 West: Gray Summit
23 m · 2 sec
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17
Exit the roundabout onto MO 100 West: Gray Summit
1202 ft · 33 sec
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18
Merge slight left
13.3 mi · 19 min
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19
Take the exit slight right toward I 44 West, US 50 West: St. Clair
1157 ft · 14 sec
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20
Merge slight left
150.1 mi · 2 hr 41 min
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21
Take the exit slight right
1345 ft · 33 sec
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22
Enter the roundabout and take exit 4 toward the route
127 m · 9 sec
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23
Exit the roundabout
148 m · 10 sec
-
24
Enter the roundabout and take exit 1 toward North Marshall Road
36 m · 3 sec · North Marshall Road
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25
Exit the roundabout onto North Marshall Road
1791 ft · 49 sec · North Marshall Road
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26
Continue on North Marshall Street
1.4 mi · 4 min · North Marshall Street
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27
At the end of the road, turn right onto West Jefferson Street
51 m · 13 sec · West Jefferson Street
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28
Turn left onto North Clay Street
46 m · 7 sec · North Clay Street
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29
Arrive at your destination
0 m · 1 sec · North Clay Street
Car Route Details
A richer read on the saved driving route between O'Fallon and Marshfield.
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 44 West
Merge slight left
150 mi · 02h 41m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A longer out-and-back drive
This is still possible in one day, but it becomes a long driving day. Leaving early and planning your stop window matters more here.
Partly Sunny then Slight Chance Rain Showers leaving O'Fallon and Chance Showers And Thunderstorms near Marshfield.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from O'Fallon to Marshfield?
The road trip is about 185.8 miles (299 km) and usually takes 03h 40m in normal driving conditions.
Is this a same-day trip or an overnight route?
This is still possible in one day, but it becomes a long driving day. Leaving early and planning your stop window matters more here.
What is the halfway point on this route?
Saint James is a useful midpoint, sitting about 92.8 miles from O'Fallon and 93 miles from Marshfield.
How much longer is the road route than the straight-line distance?
The direct path is about 157.3 miles (253.2 km), while the road route adds roughly 28.5 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 6:00 AM to 8:00 AM CDT. If you want a more comfortable same-day return, try to leave by 9:38 AM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $24.74 one way or $49.48 round trip. Estimated CO2 is about 58.3 kg one way.
What should you check before leaving?
Before you leave, expect Partly Sunny then Slight Chance Rain Showers around O'Fallon and Chance Showers And Thunderstorms near Marshfield.
Stop Ideas Near Saint James
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 Saint James.
Jefferson City
Hermann
Washington
Flight Path Map
This map shows the direct air route between O'Fallon and Marshfield. Straight-line distance: 157.33 mi (253.2 km).
#1 O'Fallon
The most populous city in St.
| Population | 89,769 |
| Coordinates | 38.8106100, -90.6998500 |
| Altitude | 165 |
| Country | United States |
#2 Marshfield
City in Missouri
| Population | 7,678 |
| Coordinates | 37.3386600, -92.9071200 |
| Altitude | 455 |
| Country | United States |
End: Marshfield (-92.90712, 37.33866)
Estimated Travel Time
Distance: 299 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 06h 11m |
| 40 mph (64.37 km/h) | 04h 38m |
| 50 mph (80.47 km/h) | 03h 42m |
| 60 mph (96.56 km/h) | 03h 05m |
| 70 mph (112.65 km/h) | 02h 39m |
| 80 mph (129 km/h) | 02h 19m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $24.74 | $49.48 |
| Mid-grade | $4.25 | $27.90 | $55.80 |
| Premium | $4.65 | $30.53 | $61.06 |
| Diesel | $5.30 | $34.79 | $69.59 |
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 26, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.