How far is Decatur, IL from Waterloo, IL?
The driving distance from Decatur, IL to Waterloo, IL is about 137 miles (220.5 km), with a travel time of about 02h 52m by car.
- The straight-line flight distance is about 122.1 miles (196.5 km).
- For a round trip, plan for roughly 05h 45m 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 52m.
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.
Human settlement in Macoupin County, Illinois, United States of America
Route Weather Snapshot
Check the forecast at both ends before you head out.
Mostly Sunny
Driving Route Map
The map below follows the saved road route between Decatur and Waterloo.
Turn-by-Turn Driving Directions
Step-by-step road directions between Decatur and Waterloo.
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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
52.3 mi · 57 min
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11
Take the exit slight right toward I 255: Memphis, Interstate 270
1386 ft · 34 sec
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12
Keep slight left to continue on I 255 South: Memphis
1.1 mi · 2 min
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13
Merge slight left
17.2 mi · 20 min
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14
Take the exit slight left toward IL 3 South: Columbia
10.4 mi · 13 min
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15
Turn left onto North Market Street
1.4 mi · 4 min · North Market Street
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16
Turn right onto West Mill Street
79 m · 11 sec · West Mill Street
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17
Arrive at your destination
0 m · 1 sec · West Mill Street
Car Route Details
A richer read on the saved driving route between Decatur and Waterloo.
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
52.3 mi · 00h 57m
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 Decatur and Mostly Sunny near Waterloo.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Decatur to Waterloo?
The road trip is about 137 miles (220.5 km) and usually takes 02h 52m 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?
Lake Ka-Ho is a useful midpoint, sitting about 68.5 miles from Decatur and 68.5 miles from Waterloo.
How much longer is the road route than the straight-line distance?
The direct path is about 122.1 miles (196.5 km), while the road route adds roughly 14.9 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 12:44 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $18.21 one way or $36.43 round trip. Estimated CO2 is about 42.9 kg one way.
What should you check before leaving?
Before you leave, expect Sunny around Decatur and Mostly Sunny near Waterloo.
Stop Ideas Near Lake Ka-Ho
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 Lake Ka-Ho.
Carlinville
Alton
Gateway Transportation Center
Springfield station
Flight Path Map
This map shows the direct air route between Decatur and Waterloo. Straight-line distance: 122.11 mi (196.52 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 Waterloo
City in Illinois
| Population | 10,536 |
| Coordinates | 38.3358900, -90.1498300 |
| Altitude | 216 |
| Country | United States |
End: Waterloo (-90.14983, 38.33589)
Estimated Travel Time
Distance: 220 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 04h 33m |
| 40 mph (64.37 km/h) | 03h 25m |
| 50 mph (80.47 km/h) | 02h 44m |
| 60 mph (96.56 km/h) | 02h 17m |
| 70 mph (112.65 km/h) | 01h 57m |
| 80 mph (129 km/h) | 01h 42m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $18.21 | $36.43 |
| Mid-grade | $4.25 | $20.54 | $41.08 |
| Premium | $4.65 | $22.48 | $44.96 |
| Diesel | $5.30 | $25.62 | $51.24 |
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 23, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.