How far is O'Fallon, MO from Thayer, MO?
The driving distance from O'Fallon, MO to Thayer, MO is about 225.2 miles (362.4 km), with a travel time of about 04h 41m by car.
- The straight-line flight distance is about 164.5 miles (264.7 km).
- For a round trip, plan for roughly 09h 22m 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 41m.
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.
Showers And Thunderstorms
Chance Showers And Thunderstorms then Showers And Thunderstorms
Driving Route Map
The map below follows the saved road route between O'Fallon and Thayer.
Turn-by-Turn Driving Directions
Step-by-step road directions between O'Fallon and Thayer.
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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
67.3 mi · 1 hr 12 min
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21
Take the exit slight right toward MO E: Rolla
910 ft · 19 sec
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22
Enter the roundabout and take exit 4 toward Tim Bradley Way
90 m · 6 sec · Tim Bradley Way
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23
Exit the roundabout onto Tim Bradley Way
2010 ft · 49 sec · Tim Bradley Way
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24
Turn slight right onto North Bishop Avenue
9 m · 1 sec · North Bishop Avenue
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25
Keep slight right to continue on North Bishop Avenue
44 m · 3 sec · North Bishop Avenue
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26
Continue on North Bishop Avenue
65.7 mi · 1 hr 23 min · North Bishop Avenue
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27
Take the ramp straight toward US 60 East, US 63 South: Willow Springs
13.9 mi · 16 min
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28
Keep slight right to continue on US 63 South: West Plains, Thayer
43.8 mi · 55 min
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29
Take the exit slight right
63 m · 7 sec
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30
Turn straight onto West Walnut Street
788 ft · 24 sec · West Walnut Street
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31
Turn right onto Front Street
133 m · 19 sec · Front Street
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32
Turn sharp right
23 m · 3 sec
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33
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between O'Fallon and Thayer.
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
67.3 mi · 01h 12m
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 leaving O'Fallon and Chance Showers And Thunderstorms then Showers And Thunderstorms near Thayer.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from O'Fallon to Thayer?
The road trip is about 225.2 miles (362.4 km) and usually takes 04h 41m 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?
Edgar Springs is a useful midpoint, sitting about 112.6 miles from O'Fallon and 112.6 miles from Thayer.
How much longer is the road route than the straight-line distance?
The direct path is about 164.5 miles (264.7 km), while the road route adds roughly 60.7 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 6:00 AM to 8:00 AM CDT. If you want a more comfortable same-day return, try to leave by 7:38 AM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $29.98 one way or $59.96 round trip. Estimated CO2 is about 70.7 kg one way.
What should you check before leaving?
Before you leave, expect Showers And Thunderstorms around O'Fallon and Chance Showers And Thunderstorms then Showers And Thunderstorms near Thayer.
Stop Ideas Near Edgar Springs
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 Edgar Springs.
Jefferson City
Hermann
Flight Path Map
This map shows the direct air route between O'Fallon and Thayer. Straight-line distance: 164.47 mi (264.69 km).
#1 O'Fallon
The most populous city in St.
| Population | 89,769 |
| Coordinates | 38.8106100, -90.6998500 |
| Altitude | 165 |
| Country | United States |
End: Thayer (-91.5382, 36.52451)
Estimated Travel Time
Distance: 362 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 07h 30m |
| 40 mph (64.37 km/h) | 05h 37m |
| 50 mph (80.47 km/h) | 04h 30m |
| 60 mph (96.56 km/h) | 03h 45m |
| 70 mph (112.65 km/h) | 03h 13m |
| 80 mph (129 km/h) | 02h 48m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $29.98 | $59.96 |
| Mid-grade | $4.25 | $33.81 | $67.62 |
| Premium | $4.65 | $37.00 | $74.00 |
| Diesel | $5.30 | $42.17 | $84.33 |
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.