How far is Decatur, IL from Troy, IL?
The driving distance from Decatur, IL to Troy, IL is about 100.7 miles (162.1 km), with a travel time of about 02h 07m by car.
- The straight-line flight distance is about 91.4 miles (147.1 km).
- For a round trip, plan for roughly 04h 15m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 8:00 AM to 10:00 AM CDT.
Reverse, save, or send this route
This route works well as a day trip with time at the destination. Copy the route link, send it to another device, or print a clean version before you head out.
This route works well as a day trip with time at the destination.
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 02h 07m.
A morning start gives you useful time at the destination and keeps the return out of the late evening.
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.
Route Weather Snapshot
Check the forecast at both ends before you head out.
Slight Chance Rain And Snow Showers then Sunny
Slight Chance Rain Showers then Sunny
Driving Route Map
The map below follows the saved road route between Decatur and Troy.
Turn-by-Turn Driving Directions
Step-by-step road directions between Decatur and Troy.
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1
Start on East Wood Street
91 m · 16 sec · East Wood Street
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2
Turn left onto South Main Street
1.3 mi · 2 min · South Main Street
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3
Turn right onto West South Side Drive
1.5 km · 1 min · West South Side Drive
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4
Turn left onto South Taylorville Road
12.9 mi · 15 min · South Taylorville Road
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5
Continue on County Road 2080 E
18.4 mi · 23 min · County Road 2080 E
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6
Continue on County Road 975 N
3056 ft · 52 sec · County Road 975 N
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7
Continue on Sarpy Street
12.2 mi · 21 min · Sarpy Street
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8
Continue on Front Street
7.6 mi · 11 min · Front Street
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9
Turn left onto I 55 South: East Saint Louis
1822 ft · 44 sec
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10
Merge slight left
44.5 mi · 48 min
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11
Take the exit slight right toward IL 162: Troy
1302 ft · 32 sec
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12
Keep slight left
141 m · 13 sec
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13
Turn straight onto Edwardsville Road
1.6 mi · 3 min · Edwardsville Road
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14
Turn left onto North Main Street
12 m · 2 sec · North Main Street
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15
Arrive at your destination
0 m · 1 sec · North Main Street
Car Route Details
A richer read on the saved driving route between Decatur and Troy.
Straightforward drive
The saved road route has a manageable number of maneuvers and should be easy to follow with normal attention to signs.
I 55 South
Merge slight left
44.5 mi · 00h 48m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A comfortable day-trip route
This route works well as a day trip. You can leave in the morning, spend meaningful time at the destination, and still return the same day.
Slight Chance Rain And Snow Showers then Sunny leaving Decatur and Slight Chance Rain Showers then Sunny near Troy.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Decatur to Troy?
The road trip is about 100.7 miles (162.1 km) and usually takes 02h 07m in normal driving conditions.
Is this a same-day trip or an overnight route?
This route works well as a day trip. You can leave in the morning, spend meaningful time at the destination, and still return the same day.
What is the halfway point on this route?
Raymond is a useful midpoint, sitting about 50.4 miles from Decatur and 50.3 miles from Troy.
How much longer is the road route than the straight-line distance?
The direct path is about 91.4 miles (147.1 km), while the road route adds roughly 9.3 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 8:00 AM to 10:00 AM CDT. If you want a more comfortable same-day return, try to leave by 2:14 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $13.39 one way or $26.77 round trip. Estimated CO2 is about 31.5 kg one way.
What should you check before leaving?
Before you leave, expect Slight Chance Rain And Snow Showers then Sunny around Decatur and Slight Chance Rain Showers then Sunny near Troy.
Stop Ideas Near Raymond
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 Raymond.
Carlinville
Springfield station
Alton
Effingham
Flight Path Map
This map shows the direct air route between Decatur and Troy. Straight-line distance: 91.42 mi (147.13 km).
#1 Decatur
The most populous city in Macon County, Illinois.
| Population | 70,007 |
| Coordinates | 39.8403100, -88.9548000 |
| Altitude | 205 |
| Country | United States |
#2 Troy
City in Madison County, Illinois, United States
| Population | 10,399 |
| Coordinates | 38.7292100, -89.8831500 |
| Altitude | 171 |
| Country | United States |
End: Troy (-89.88315, 38.72921)
Estimated Travel Time
Distance: 162 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 03h 21m |
| 40 mph (64.37 km/h) | 02h 31m |
| 50 mph (80.47 km/h) | 02h 00m |
| 60 mph (96.56 km/h) | 01h 40m |
| 70 mph (112.65 km/h) | 01h 26m |
| 80 mph (129 km/h) | 01h 15m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $13.39 | $26.77 |
| Mid-grade | $4.25 | $15.10 | $30.20 |
| Premium | $4.65 | $16.52 | $33.04 |
| Diesel | $5.30 | $18.83 | $37.66 |
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 Illinois · Apr 19, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.