How far is Troy, MO from Decatur, IL?
The driving distance from Troy, MO to Decatur, IL is about 171.9 miles (276.7 km), with a travel time of about 03h 27m by car.
- The straight-line flight distance is about 123.4 miles (198.6 km).
- For a round trip, plan for roughly 06h 54m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 6:00 AM to 8:00 AM CST.
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 27m.
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.
County seat of Scott County, Illinois, USA
Route Weather Snapshot
Check the forecast at both ends before you head out.
Chance Rain Showers then Patchy Fog
Chance Rain Showers
Driving Route Map
The map below follows the saved road route between Troy and Decatur.
Turn-by-Turn Driving Directions
Step-by-step road directions between Troy and Decatur.
-
1
Start on the route
30 m · 12 sec
-
2
At the end of the road, turn left onto 2nd Street
30 m · 7 sec · 2nd Street
-
3
Turn right onto East Cherry Street
1042 ft · 21 sec · East Cherry Street
-
4
Enter the roundabout and take exit 1 toward East Cherry Street
35 m · 3 sec · East Cherry Street
-
5
Exit the roundabout onto East Cherry Street
2215 ft · 50 sec · East Cherry Street
-
6
Turn left onto North Lincoln Drive
1177 ft · 24 sec · North Lincoln Drive
-
7
Turn slight right
63 m · 8 sec
-
8
Turn slight right
1303 ft · 39 sec
-
9
Take the ramp slight left toward US 61 North: Hannibal
981 ft · 14 sec
-
10
Merge slight left onto Avenue of the Saints
31.4 mi · 37 min · Avenue of the Saints
-
11
Take the exit slight right toward US 54: Mexico, Louisiana
1467 ft · 31 sec
-
12
Turn slight right
38 m · 3 sec
-
13
Turn right
30.1 mi · 43 min
-
14
Turn left onto North Jackson Street
5.1 mi · 8 min · North Jackson Street
-
15
Take the ramp right toward I 72 East, US 36 East: Springfield
1361 ft · 33 sec
-
16
Merge slight left
67.2 mi · 1 hr 12 min
-
17
Take the exit slight right toward I 72 East, US 36 East: Decatur
30 mi · 33 min
-
18
Take the exit slight right toward US 36 East, US 51 South: Decatur, Pana
1656 ft · 41 sec
-
19
Keep slight left to continue on US 36 East: Decatur
5.5 mi · 8 min
-
20
Turn right onto North Main Street
1985 ft · 49 sec · North Main Street
-
21
Turn left onto East Wood Street
91 m · 8 sec · East Wood Street
-
22
Arrive at your destination
0 m · 1 sec · East Wood Street
Car Route Details
A richer read on the saved driving route between Troy and Decatur.
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 72 East
Merge slight left
67.2 mi · 01h 13m
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.
Chance Rain Showers then Patchy Fog leaving Troy and Chance Rain Showers near Decatur.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Troy to Decatur?
The road trip is about 171.9 miles (276.7 km) and usually takes 03h 27m 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?
Winchester is a useful midpoint, sitting about 85.9 miles from Troy and 86.1 miles from Decatur.
How much longer is the road route than the straight-line distance?
The direct path is about 123.4 miles (198.6 km), while the road route adds roughly 48.5 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 CST. If you want a more comfortable same-day return, try to leave by 10:06 AM CST.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $23.43 one way or $46.86 round trip. Estimated CO2 is about 53.9 kg one way.
What should you check before leaving?
Before you leave, expect Chance Rain Showers then Patchy Fog around Troy and Chance Rain Showers near Decatur.
Stop Ideas Near Winchester
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 Winchester.
Carlinville
Springfield station
Alton
Quincy
Flight Path Map
This map shows the direct air route between Troy and Decatur. Straight-line distance: 123.42 mi (198.63 km).
#1 Troy
City in Lincoln County, Montana, USA
| Population | 13,341 |
| Coordinates | 38.9794900, -90.9807000 |
| Altitude | 165 |
| Country | United States |
#2 Decatur
The most populous city in Macon County, Illinois.
| Population | 70,007 |
| Coordinates | 39.8403100, -88.9548000 |
| Altitude | 205 |
| Country | United States |
End: Decatur (-88.9548, 39.84031)
Estimated Travel Time
Distance: 277 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 05h 43m |
| 40 mph (64.37 km/h) | 04h 17m |
| 50 mph (80.47 km/h) | 03h 26m |
| 60 mph (96.56 km/h) | 02h 51m |
| 70 mph (112.65 km/h) | 02h 27m |
| 80 mph (129 km/h) | 02h 08m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.86 | $23.43 | $46.86 |
| Mid-grade | $4.22 | $25.60 | $51.21 |
| Premium | $4.59 | $27.84 | $55.69 |
| Diesel | $6.07 | $36.81 | $73.63 |
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 · Nov 01, 2026