How far is Des Plaines, IL from Monmouth, IL?
The driving distance from Des Plaines, IL to Monmouth, IL is about 211.5 miles (340.3 km), with a travel time of about 03h 59m by car.
- The straight-line flight distance is about 162.7 miles (261.9 km).
- For a round trip, plan for roughly 07h 59m 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 03h 59m.
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.
Village in Lee County, Illinois, United States of America
Route Weather Snapshot
Check the forecast at both ends before you head out.
Mostly Sunny
Slight Chance Showers And Thunderstorms then Mostly Cloudy
Driving Route Map
The map below follows the saved road route between Des Plaines and Monmouth.
Turn-by-Turn Driving Directions
Step-by-step road directions between Des Plaines and Monmouth.
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1
Start on Henry Avenue
557 ft · 25 sec · Henry Avenue
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2
Turn right onto South Des Plaines River Road
1.8 mi · 3 min · South Des Plaines River Road
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3
Take the ramp slight right toward I 294 South: Indiana
2265 ft · 55 sec
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4
Merge slight left onto Tri-State Tollway
8.9 mi · 12 min · Tri-State Tollway
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5
Take the exit slight right toward I 88 West, I 294 South: Aurora, Indiana
1.5 km · 2 min · Tri-State Tollway
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6
Keep slight right to continue on Tri-State Tollway
1251 ft · 31 sec · Tri-State Tollway
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7
Continue on Tri-State Tollway
1937 ft · 47 sec · Tri-State Tollway
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8
Keep slight right to continue on I 88 West Toll: Aurora
2633 ft · 50 sec
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9
Merge slight left onto Ronald Reagan Memorial Tollway
1.2 km · 60 sec · Ronald Reagan Memorial Tollway
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10
Keep slight right to continue on Ronald Reagan Memorial Tollway
25.1 mi · 30 min · Ronald Reagan Memorial Tollway
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11
Keep slight left to continue on Ronald Reagan Memorial Tollway
69.5 mi · 1 hr 14 min · Ronald Reagan Memorial Tollway
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12
Continue on Ronald Reagan Memorial Highway
1.1 mi · 1 min · Ronald Reagan Memorial Highway
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13
Continue on Ronald Reagan Memorial Highway
37.8 mi · 40 min · Ronald Reagan Memorial Highway
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14
Continue on Chicago-Kansas City Expressway
5.4 mi · 6 min · Chicago-Kansas City Expressway
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15
Take the exit slight right toward I 80: Peoria
7.1 mi · 8 min
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16
Keep slight left to continue on Chicago-Kansas City Expressway
31.3 mi · 34 min · Chicago-Kansas City Expressway
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17
Take the exit slight right toward US 34 West: Monmouth
19.1 mi · 23 min
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18
Turn left onto North Main Street
1.5 km · 2 min · North Main Street
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19
Enter the roundabout and take exit 3 toward Public Square
94 m · 6 sec · East Broadway
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20
Exit the rotary onto East Broadway
90 m · 10 sec · East Broadway
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21
Turn right onto South 1st Street
65 m · 9 sec · South 1st Street
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22
Arrive at your destination
0 m · 1 sec · South 1st Street
Car Route Details
A richer read on the saved driving route between Des Plaines and Monmouth.
Interchange-aware route
The drive includes several ramps, exits, or merges, so checking the next few maneuvers before busy interchanges is useful.
Ronald Reagan Memorial Tollway
Keep slight left to continue on Ronald Reagan Memorial Tollway
69.5 mi · 01h 14m
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.
Mostly Sunny leaving Des Plaines and Slight Chance Showers And Thunderstorms then Mostly Cloudy near Monmouth.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Des Plaines to Monmouth?
The road trip is about 211.5 miles (340.3 km) and usually takes 03h 59m 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?
Nelson is a useful midpoint, sitting about 105.6 miles from Des Plaines and 105.9 miles from Monmouth.
How much longer is the road route than the straight-line distance?
The direct path is about 162.7 miles (261.9 km), while the road route adds roughly 48.8 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 9:00 AM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $28.13 one way or $56.26 round trip. Estimated CO2 is about 66.3 kg one way.
What should you check before leaving?
Before you leave, expect Mostly Sunny around Des Plaines and Slight Chance Showers And Thunderstorms then Mostly Cloudy near Monmouth.
Stop Ideas Near Nelson
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 Nelson.
Princeton
Mendota station
Kewanee
Rockford, Illinois
Flight Path Map
This map shows the direct air route between Des Plaines and Monmouth. Straight-line distance: 162.72 mi (261.88 km).
#1 Des Plaines
The most populous city in Cook County, Illinois.
| Population | 58,179 |
| Coordinates | 42.0333600, -87.8834000 |
| Altitude | 193 |
| Country | United States |
#2 Monmouth
City in Warren County, Illinois, United States
| Population | 8,801 |
| Coordinates | 40.9114300, -90.6473600 |
| Altitude | 232 |
| Country | United States |
End: Monmouth (-90.64736, 40.91143)
Estimated Travel Time
Distance: 340 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 07h 02m |
| 40 mph (64.37 km/h) | 05h 17m |
| 50 mph (80.47 km/h) | 04h 13m |
| 60 mph (96.56 km/h) | 03h 31m |
| 70 mph (112.65 km/h) | 03h 01m |
| 80 mph (129 km/h) | 02h 38m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $28.13 | $56.26 |
| Mid-grade | $4.25 | $31.73 | $63.45 |
| Premium | $4.65 | $34.72 | $69.44 |
| Diesel | $5.30 | $39.57 | $79.14 |
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 · May 31, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.