How far is Mount Vernon, IL from Decatur, IL?
The driving distance from Mount Vernon, IL to Decatur, IL is about 121.2 miles (195.1 km), with a travel time of about 02h 20m by car.
- The straight-line flight distance is about 105.3 miles (169.4 km).
- For a round trip, plan for roughly 04h 41m 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 20m.
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 Fayette County, Illinois
Route Weather Snapshot
Check the forecast at both ends before you head out.
Mostly Sunny then Chance Showers And Thunderstorms
Mostly Sunny then Chance Showers And Thunderstorms
Driving Route Map
The map below follows the saved road route between Mount Vernon and Decatur.
Turn-by-Turn Driving Directions
Step-by-step road directions between Mount Vernon and Decatur.
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1
Start on Broadway Street
44 m · 10 sec · Broadway Street
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2
Turn left onto South 9th Street
87 m · 20 sec · South 9th Street
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3
Turn left onto Main Street
2130 ft · 40 sec · Main Street
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4
Turn straight onto Broadway Street
2.2 mi · 4 min · Broadway Street
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5
Take the ramp slight right
1350 ft · 22 sec
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6
Merge slight left onto Ken Gray Expressway
1.1 mi · 1 min · Ken Gray Expressway
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7
Keep slight right to continue on Ken Gray Expressway
20.5 mi · 22 min · Ken Gray Expressway
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8
Take the exit slight right toward US 50: Salem, Sandoval
2199 ft · 54 sec
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9
Merge slight left onto West Main Street
2.4 mi · 3 min · West Main Street
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10
Continue on East Poplar Street
2.7 mi · 3 min · East Poplar Street
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11
Continue on Poplar
2.7 mi · 3 min · Poplar
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12
Turn right onto 150E
10.4 mi · 12 min · 150E
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13
Continue on 300E
13.5 mi · 15 min · 300E
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14
Turn left
2405 ft · 35 sec
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15
Turn right onto North Kennedy Boulevard
1.6 mi · 2 min · North Kennedy Boulevard
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16
Continue on County Road 875 East
11.1 mi · 13 min · County Road 875 East
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17
Continue on South Superior Street
15.1 mi · 17 min · South Superior Street
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18
Continue on County Road 2400 East
2 mi · 3 min · County Road 2400 East
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19
Continue on Fair Avenue
3070 ft · 2 min · Fair Avenue
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20
Continue on South Poplar Street
2138 ft · 32 sec · South Poplar Street
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21
Turn right onto East 1st Street
2150 ft · 1 min · East 1st Street
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22
Turn left onto Cedar Street
116 m · 5 sec · Cedar Street
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23
Turn right onto Jackson Street
2709 ft · 2 min · Jackson Street
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24
Continue on North 2600 East Road
1.6 km · 2 min · North 2600 East Road
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25
Turn left
28.7 mi · 33 min
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26
Take the exit slight right toward Decatur
2582 ft · 1 min
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27
Keep slight right to continue on Decatur
44 m · 4 sec
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28
Turn straight onto South Business Route 51
2.6 mi · 4 min · South Business Route 51
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29
Continue on South Main Street
769 ft · 19 sec · South Main Street
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30
Continue on South Franklin Street
1.2 mi · 2 min · South Franklin Street
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31
Turn left onto East Wood Street
155 m · 16 sec · East Wood Street
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32
Arrive at your destination
0 m · 1 sec · East Wood Street
Car Route Details
A richer read on the saved driving route between Mount Vernon and Decatur.
Interchange-aware route
The drive includes several ramps, exits, or merges, so checking the next few maneuvers before busy interchanges is useful.
Longest stretch
Turn left
28.7 mi · 00h 33m
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.
Mostly Sunny then Chance Showers And Thunderstorms leaving Mount Vernon and Mostly Sunny then Chance Showers And Thunderstorms near Decatur.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Mount Vernon to Decatur?
The road trip is about 121.2 miles (195.1 km) and usually takes 02h 20m 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?
Vandalia is a useful midpoint, sitting about 61.6 miles from Mount Vernon and 59.7 miles from Decatur.
How much longer is the road route than the straight-line distance?
The direct path is about 105.3 miles (169.4 km), while the road route adds roughly 15.9 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 1:48 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $16.14 one way or $32.28 round trip. Estimated CO2 is about 38 kg one way.
What should you check before leaving?
Before you leave, expect Mostly Sunny then Chance Showers And Thunderstorms around Mount Vernon and Mostly Sunny then Chance Showers And Thunderstorms near Decatur.
Stop Ideas Near Vandalia
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 Vandalia.
Centralia station
Effingham
Mt. Vernon, IL
Carlinville
Flight Path Map
This map shows the direct air route between Mount Vernon and Decatur. Straight-line distance: 105.27 mi (169.41 km).
#1 Mount Vernon
City located near the center of Jefferson County, Illinois, United States
| Population | 14,511 |
| Coordinates | 38.3172700, -88.9031200 |
| Altitude | 156 |
| 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: 195 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 04h 02m |
| 40 mph (64.37 km/h) | 03h 01m |
| 50 mph (80.47 km/h) | 02h 25m |
| 60 mph (96.56 km/h) | 02h 01m |
| 70 mph (112.65 km/h) | 01h 43m |
| 80 mph (129 km/h) | 01h 30m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $16.14 | $32.28 |
| Mid-grade | $4.25 | $18.20 | $36.41 |
| Premium | $4.65 | $19.92 | $39.84 |
| Diesel | $5.30 | $22.70 | $45.40 |
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 18, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.