How far is O'Fallon, MO from Castor, MO?
The driving distance from O'Fallon, MO to Castor, MO is about 167.8 miles (270.1 km), with a travel time of about 03h 24m by car.
- The straight-line flight distance is about 126.7 miles (203.9 km).
- For a round trip, plan for roughly 06h 49m 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 24m.
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 and the county seat of Ste.
Route Weather Snapshot
Check the forecast at both ends before you head out.
Showers And Thunderstorms Likely then Chance Showers And Thunderstorms
Slight Chance Showers And Thunderstorms
Driving Route Map
The map below follows the saved road route between O'Fallon and Castor.
Turn-by-Turn Driving Directions
Step-by-step road directions between O'Fallon and Castor.
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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
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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
19 mi · 24 min
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10
Take the exit slight right toward I 55, US 61, US 67: Saint Louis, Memphis, Lemay Ferry Road
1911 ft · 27 sec
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11
Keep slight right to continue on I 55 South: Memphis
2031 ft · 44 sec
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12
Merge slight left onto Rosa Parks Highway
1.5 mi · 2 min · Rosa Parks Highway
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13
Continue on Officer Thomas G. Smith, Jr. Memorial Highway
1.8 mi · 2 min · Officer Thomas G. Smith, Jr. Memorial Highway
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14
Continue on Police Officer Steven Jarvis Memorial Highway
101 mi · 1 hr 48 min · Police Officer Steven Jarvis Memorial Highway
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15
Take the exit slight right toward MO AB: Cape Girardeau Regional Airport
954 ft · 20 sec
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16
Keep slight right to continue on MO AB: Cape Girardeau Regional Airport
49 m · 4 sec
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17
Turn right onto Nash Road
5.6 mi · 8 min · Nash Road
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18
Enter the roundabout and take exit 2 toward MO 25 South: Delta
58 m · 4 sec
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19
Exit the roundabout onto MO 25 South: Delta
15.8 mi · 24 min
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20
Continue straight
2094 ft · 37 sec
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21
Continue straight
2.6 mi · 5 min
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22
Turn left
1.5 mi · 3 min
-
23
Turn right onto County Road 640
1.7 mi · 7 min · County Road 640
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24
Arrive at your destination
0 m · 1 sec · County Road 640
Car Route Details
A richer read on the saved driving route between O'Fallon and Castor.
Highway-focused drive
Most of the mileage stays on named highways, so the important moments are ramps, exits, merges, and the final local approach.
Police Officer Steven Jarvis Memorial Highway
Continue on Police Officer Steven Jarvis Memorial Highway
101 mi · 01h 48m
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.
Showers And Thunderstorms Likely then Chance Showers And Thunderstorms leaving O'Fallon and Slight Chance Showers And Thunderstorms near Castor.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from O'Fallon to Castor?
The road trip is about 167.8 miles (270.1 km) and usually takes 03h 24m 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?
Sainte Genevieve is a useful midpoint, sitting about 83.9 miles from O'Fallon and 83.9 miles from Castor.
How much longer is the road route than the straight-line distance?
The direct path is about 126.7 miles (203.9 km), while the road route adds roughly 41.1 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 10:10 AM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $22.32 one way or $44.65 round trip. Estimated CO2 is about 52.6 kg one way.
What should you check before leaving?
Before you leave, expect Showers And Thunderstorms Likely then Chance Showers And Thunderstorms around O'Fallon and Slight Chance Showers And Thunderstorms near Castor.
Stop Ideas Near Sainte Genevieve
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 Sainte Genevieve.
Du Quoin
Gateway Transportation Center
Kirkwood
Carbondale station
Flight Path Map
This map shows the direct air route between O'Fallon and Castor. Straight-line distance: 126.68 mi (203.87 km).
#1 O'Fallon
The most populous city in St.
| Population | 89,769 |
| Coordinates | 38.8106100, -90.6998500 |
| Altitude | 165 |
| Country | United States |
#2 Castor
Unincorporated community in Missouri
| Population | 4,951 |
| Coordinates | 37.0675500, -89.9787100 |
| Altitude | 107 |
| Country | United States |
End: Castor (-89.97871, 37.06755)
Estimated Travel Time
Distance: 270 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 05h 35m |
| 40 mph (64.37 km/h) | 04h 11m |
| 50 mph (80.47 km/h) | 03h 21m |
| 60 mph (96.56 km/h) | 02h 47m |
| 70 mph (112.65 km/h) | 02h 23m |
| 80 mph (129 km/h) | 02h 05m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $22.32 | $44.65 |
| Mid-grade | $4.25 | $25.18 | $50.36 |
| Premium | $4.65 | $27.55 | $55.10 |
| Diesel | $5.30 | $31.40 | $62.80 |
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 · Jun 01, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.