How far is Alton, IL from Decatur, IL?
The driving distance from Alton, IL to Decatur, IL is about 107.4 miles (172.8 km), with a travel time of about 02h 05m by car.
- The straight-line flight distance is about 92.8 miles (149.4 km).
- For a round trip, plan for roughly 04h 10m 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 05m.
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.
Township in Montgomery County, Illinois
Route Weather Snapshot
Check the forecast at both ends before you head out.
Slight Chance Rain And Snow Showers then Sunny
Driving Route Map
The map below follows the saved road route between Alton and Decatur.
Turn-by-Turn Driving Directions
Step-by-step road directions between Alton and Decatur.
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1
Start on Alby Street
58 m · 10 sec · Alby Street
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2
Turn right onto East Broadway
649 ft · 22 sec · East Broadway
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3
Turn right onto Piasa Street
2192 ft · 37 sec · Piasa Street
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4
Continue on Martin Luther King Drive
1.5 km · 1 min · Martin Luther King Drive
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5
Turn right onto College Avenue
1274 ft · 26 sec · College Avenue
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6
Turn right
20 m · 1 sec
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7
Enter the roundabout and take exit 2 toward College Avenue
116 m · 10 sec · College Avenue
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8
Exit the roundabout onto College Avenue
3.6 mi · 6 min · College Avenue
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9
Continue on West Macarthur Drive
1.3 mi · 2 min · West Macarthur Drive
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10
Continue on West MacArthur Drive
1.4 mi · 3 min · West MacArthur Drive
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11
Continue on West Bethalto Drive
1.8 mi · 4 min · West Bethalto Drive
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12
Continue on State Route 140
9.6 mi · 13 min · State Route 140
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13
Continue on West State Street
1.3 km · 2 min · West State Street
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14
Continue on State Route 140
135 m · 14 sec · State Route 140
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15
Take the ramp left
1515 ft · 38 sec
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16
Merge slight left
32.8 mi · 35 min
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17
Take the exit slight right toward IL 48, IL 127: Raymond, Taylorville, Hillsboro
1658 ft · 31 sec
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18
Keep slight right to continue on IL 48, IL 127: Raymond, Taylorville, Hillsboro
45 m · 3 sec
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19
Turn straight onto North 22nd Avenue
7.2 mi · 11 min · North 22nd Avenue
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20
Continue on Sarpy Street
12.2 mi · 21 min · Sarpy Street
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21
Continue on County Road 975 N
3056 ft · 52 sec · County Road 975 N
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22
Continue on Jaycee Drive
18.4 mi · 23 min · Jaycee Drive
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23
Continue on North Railroad Avenue
12.9 mi · 15 min · North Railroad Avenue
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24
Turn right onto West South Side Drive
1.3 km · 1 min · West South Side Drive
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25
Turn slight left
1.4 mi · 3 min
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26
Turn left onto East Wood Street
155 m · 16 sec · East Wood Street
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27
Arrive at your destination
0 m · 1 sec · East Wood Street
Car Route Details
A richer read on the saved driving route between Alton and Decatur.
Interchange-aware route
The drive includes several ramps, exits, or merges, so checking the next few maneuvers before busy interchanges is useful.
State Route 140
Merge slight left
32.8 mi · 00h 35m
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.
Sunny leaving Alton and Slight Chance Rain And Snow Showers then Sunny near Decatur.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Alton to Decatur?
The road trip is about 107.4 miles (172.8 km) and usually takes 02h 05m 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?
Zanesville is a useful midpoint, sitting about 53.6 miles from Alton and 53.7 miles from Decatur.
How much longer is the road route than the straight-line distance?
The direct path is about 92.8 miles (149.4 km), while the road route adds roughly 14.6 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 2:20 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $14.29 one way or $28.58 round trip. Estimated CO2 is about 33.7 kg one way.
What should you check before leaving?
Before you leave, expect Sunny around Alton and Slight Chance Rain And Snow Showers then Sunny near Decatur.
Stop Ideas Near Zanesville
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 Zanesville.
Carlinville
Springfield station
Alton
Gateway Transportation Center
Flight Path Map
This map shows the direct air route between Alton and Decatur. Straight-line distance: 92.84 mi (149.41 km).
#1 Alton
City in Madison County, Illinois, United States
| Population | 26,049 |
| Coordinates | 38.8906000, -90.1842800 |
| Altitude | 150 |
| 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: East Wood Street (-88.954801, 39.840341)
Estimated Travel Time
Distance: 173 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 03h 34m |
| 40 mph (64.37 km/h) | 02h 41m |
| 50 mph (80.47 km/h) | 02h 08m |
| 60 mph (96.56 km/h) | 01h 47m |
| 70 mph (112.65 km/h) | 01h 32m |
| 80 mph (129 km/h) | 01h 20m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $14.29 | $28.58 |
| Mid-grade | $4.25 | $16.12 | $32.24 |
| Premium | $4.65 | $17.64 | $35.28 |
| Diesel | $5.30 | $20.10 | $40.20 |
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.