How far is Princeton, MO from O'Fallon, MO?
The driving distance from Princeton, MO to O'Fallon, MO is about 249.7 miles (401.9 km), with a travel time of about 04h 09m by car.
- The straight-line flight distance is about 188.6 miles (303.6 km).
- For a round trip, plan for roughly 08h 18m 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 04h 09m.
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 Shelby County, Missouri
Route Weather Snapshot
Check the forecast at both ends before you head out.
Rain Showers Likely
Showers And Thunderstorms
Driving Route Map
The map below follows the saved road route between Princeton and O'Fallon.
Turn-by-Turn Driving Directions
Step-by-step road directions between Princeton and O'Fallon.
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1
Start on North College Street
39 m · 3 sec · North College Street
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2
Turn left
46.5 mi · 1 hr 12 min
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3
Take the ramp left toward US 36 East, MO 110 East: Brookfield
975 ft · 13 sec
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4
Merge slight left onto Chicago-Kansas City Expressway
111.4 mi · 2 hr 9 min · Chicago-Kansas City Expressway
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5
Continue on V.F.W. Memorial Highway
5.8 mi · 7 min · V.F.W. Memorial Highway
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6
Take the exit slight right toward Veterans Road
1167 ft · 30 sec
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7
Turn right onto Veterans Road
2.1 mi · 4 min · Veterans Road
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8
At the end of the road, turn left onto County Road 422
85 m · 7 sec · County Road 422
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9
Continue on Paris Gravel Road
2539 ft · 1 min · Paris Gravel Road
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10
Take the ramp right
37 m · 3 sec
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11
Merge slight left onto Avenue of the Saints
73.7 mi · 1 hr 27 min · Avenue of the Saints
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12
Take the exit slight left toward I 70 East: Saint Louis
2705 ft · 51 sec
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13
Merge slight left onto Dwight D Eisenhower Highway
6.4 mi · 8 min · Dwight D Eisenhower Highway
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14
Take the exit slight right toward MO K: O'Fallon
1765 ft · 43 sec
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15
Turn straight onto Drennen Parkway
46 m · 3 sec · Drennen Parkway
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16
Keep slight right to continue on Drennen Parkway
51 m · 6 sec · Drennen Parkway
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17
Turn slight left onto MO K: O'Fallon
19 m · 3 sec
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18
Continue on South Main Street
3115 ft · 2 min · South Main Street
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19
Turn right
8 m · 2 sec
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20
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between Princeton and O'Fallon.
Interchange-aware route
The drive includes several ramps, exits, or merges, so checking the next few maneuvers before busy interchanges is useful.
Chicago-Kansas City Expressway
Merge slight left onto Chicago-Kansas City Expressway
111 mi · 02h 09m
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.
Rain Showers Likely leaving Princeton and Showers And Thunderstorms near O'Fallon.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Princeton to O'Fallon?
The road trip is about 249.7 miles (401.9 km) and usually takes 04h 09m 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?
Shelbina is a useful midpoint, sitting about 124.1 miles from Princeton and 125.6 miles from O'Fallon.
How much longer is the road route than the straight-line distance?
The direct path is about 188.6 miles (303.6 km), while the road route adds roughly 61.1 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 8:42 AM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $33.22 one way or $66.45 round trip. Estimated CO2 is about 78.3 kg one way.
What should you check before leaving?
Before you leave, expect Rain Showers Likely around Princeton and Showers And Thunderstorms near O'Fallon.
Stop Ideas Near Shelbina
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 Shelbina.
La Plata
Quincy
Flight Path Map
This map shows the direct air route between Princeton and O'Fallon. Straight-line distance: 188.63 mi (303.57 km).
#1 Princeton
City in Mercer County, Missouri
| Population | 1,078 |
| Coordinates | 40.4008400, -93.5805000 |
| Altitude | 293 |
| 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: 402 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 08h 19m |
| 40 mph (64.37 km/h) | 06h 14m |
| 50 mph (80.47 km/h) | 04h 59m |
| 60 mph (96.56 km/h) | 04h 09m |
| 70 mph (112.65 km/h) | 03h 34m |
| 80 mph (129 km/h) | 03h 06m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $33.22 | $66.45 |
| Mid-grade | $4.25 | $37.47 | $74.94 |
| Premium | $4.65 | $41.00 | $82.00 |
| Diesel | $5.30 | $46.73 | $93.46 |
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 · May 05, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.