How far is Decatur, IL from Lake Forest, IL?
The driving distance from Decatur, IL to Lake Forest, IL is about 205.2 miles (330.3 km), with a travel time of about 04h 07m by car.
- The straight-line flight distance is about 176.9 miles (284.7 km).
- For a round trip, plan for roughly 08h 15m 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 04h 07m.
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 Illinois
Route Weather Snapshot
Check the forecast at both ends before you head out.
Partly Sunny
Partly Sunny
Driving Route Map
The map below follows the saved road route between Decatur and Lake Forest.
Turn-by-Turn Driving Directions
Step-by-step road directions between Decatur and Lake Forest.
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1
Start on East Wood Street
155 m · 23 sec · East Wood Street
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2
Turn left onto South Franklin Street
2129 ft · 46 sec · South Franklin Street
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3
Continue on North Water Street
27.4 mi · 37 min · North Water Street
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4
Continue on North 1450 East Road
14.7 mi · 18 min · North 1450 East Road
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5
Take the exit slight right toward I 74 West, US 51 North: Peoria, Rockford
122.1 mi · 2 hr 16 min
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6
Take the exit slight right toward I 294 Tollway North: Wisconsin
1.6 mi · 3 min
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7
Keep slight left to continue on I 294 North: Wisconsin
1694 ft · 41 sec
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8
Merge slight left onto Tri-State Tollway
4.8 mi · 6 min · Tri-State Tollway
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9
Keep slight left to continue on Tri-State Tollway
29 mi · 36 min · Tri-State Tollway
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10
Take the exit slight right toward IL 60: Town Line Road
2941 ft · 58 sec
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11
Turn straight onto East Townline Road
2448 ft · 52 sec · East Townline Road
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12
Continue on Townline Road
1.6 km · 2 min · Townline Road
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13
Continue on W Kennedy Road
2498 ft · 49 sec · W Kennedy Road
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14
At the end of the road, turn left onto South Skokie Highway
1396 ft · 30 sec · South Skokie Highway
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15
Take the exit slight right
1302 ft · 38 sec
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16
Turn right onto West Deerpath
1.2 mi · 3 min · West Deerpath
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17
Turn left onto North McKinley Road
2419 ft · 52 sec · North McKinley Road
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18
Turn slight right onto East Woodland Road
62 m · 7 sec · East Woodland Road
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19
Turn slight left onto Griffith Road
22 m · 3 sec · Griffith Road
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20
Arrive at your destination
0 m · 1 sec · Griffith Road
Car Route Details
A richer read on the saved driving route between Decatur and Lake Forest.
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 74 West
Take the exit slight right toward I 74 West, US 51 North: Peoria, Rockford
122 mi · 02h 16m
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.
Partly Sunny leaving Decatur and Partly Sunny near Lake Forest.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Decatur to Lake Forest?
The road trip is about 205.2 miles (330.3 km) and usually takes 04h 07m 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?
Dwight is a useful midpoint, sitting about 102.7 miles from Decatur and 102.6 miles from Lake Forest.
How much longer is the road route than the straight-line distance?
The direct path is about 176.9 miles (284.7 km), while the road route adds roughly 28.3 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 6:00 AM to 8:00 AM CDT. If you want a more comfortable same-day return, try to leave by 8:44 AM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $27.30 one way or $54.60 round trip. Estimated CO2 is about 64.3 kg one way.
What should you check before leaving?
Before you leave, expect Partly Sunny around Decatur and Partly Sunny near Lake Forest.
Stop Ideas Near Dwight
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 Dwight.
Dwight station
Pontiac station
Kankakee
Gilman
Flight Path Map
This map shows the direct air route between Decatur and Lake Forest. Straight-line distance: 176.89 mi (284.67 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 Lake Forest
City in Lake County, Illinois, United States
| Population | 19,379 |
| Coordinates | 42.2586300, -87.8406300 |
| Altitude | 210 |
| Country | United States |
End: Lake Forest (-87.84063, 42.25863)
Estimated Travel Time
Distance: 330 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 06h 50m |
| 40 mph (64.37 km/h) | 05h 07m |
| 50 mph (80.47 km/h) | 04h 06m |
| 60 mph (96.56 km/h) | 03h 25m |
| 70 mph (112.65 km/h) | 02h 55m |
| 80 mph (129 km/h) | 02h 33m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $27.30 | $54.60 |
| Mid-grade | $4.25 | $30.79 | $61.58 |
| Premium | $4.65 | $33.69 | $67.39 |
| Diesel | $5.30 | $38.40 | $76.80 |
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 30, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.