How far is Union, MO from Saint Peters, MO?
The driving distance from Union, MO to Saint Peters, MO is about 46.6 miles (75 km), with a travel time of about 00h 57m by car.
- The straight-line flight distance is about 31.8 miles (51.2 km).
- For a round trip, plan for roughly 01h 54m 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 00h 57m.
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.
City in Saint Charles County, Missouri, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Slight Chance Rain Showers then Mostly Sunny
Driving Route Map
The map below follows the saved road route between Union and Saint Peters.
Turn-by-Turn Driving Directions
Step-by-step road directions between Union and Saint Peters.
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1
Start on the route
19 m · 7 sec
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2
Turn right onto East Park Avenue
900 ft · 31 sec · East Park Avenue
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3
Turn left onto North Church Street
1.1 km · 2 min · North Church Street
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4
Turn right onto East Independence Drive
63 m · 11 sec · East Independence Drive
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5
Turn left
9.9 mi · 15 min
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6
Turn right
1.2 km · 2 min
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7
Continue straight
3.5 mi · 6 min
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8
At the end of the road, turn left
3.1 mi · 4 min
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9
Continue straight
4.9 mi · 7 min
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10
Turn left
7.2 mi · 11 min
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11
Take the ramp right toward I 70 East, US 40 East: Saint Louis
959 ft · 13 sec
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12
Merge slight left onto Dwight D Eisenhower Highway
12.3 mi · 15 min · Dwight D Eisenhower Highway
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13
Take the exit slight right toward Mid Rivers Mall Drive
889 ft · 19 sec
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14
Keep slight left to continue on Mid Rivers Mall Drive
63 m · 4 sec
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15
Turn straight onto Mid Rivers Mall Drive
61 m · 6 sec · Mid Rivers Mall Drive
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16
Take the ramp straight toward I 70 West: Wentzville
1419 ft · 20 sec
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17
Merge slight left
146 m · 7 sec
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18
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between Union and Saint Peters.
Turn-heavy local drive
The route has frequent decision points for its length, so lane choice and turn timing will matter more than cruising speed.
Dwight D Eisenhower Highway
Merge slight left onto Dwight D Eisenhower Highway
12.3 mi · 00h 15m
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 leaving Union and Slight Chance Rain Showers then Mostly Sunny near Saint Peters.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Union to Saint Peters?
The road trip is about 46.6 miles (75 km) and usually takes 00h 57m 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?
New Melle is a useful midpoint, sitting about 21.7 miles from Union and 24.9 miles from Saint Peters.
How much longer is the road route than the straight-line distance?
The direct path is about 31.8 miles (51.2 km), while the road route adds roughly 14.8 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 8:00 AM to 10:00 AM CDT. If you want a more comfortable same-day return, try to leave by 4:36 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $6.18 one way or $12.37 round trip. Estimated CO2 is about 14.6 kg one way.
What should you check before leaving?
Before you leave, expect Mostly Sunny around Union and Slight Chance Rain Showers then Mostly Sunny near Saint Peters.
Stop Ideas Near New Melle
Useful break, food, and waypoint ideas within about 15 miles of the route midpoint.
City Hall Park
City of O'Fallon
Transit and Meeting Points
Useful pickup, handoff, or rendezvous points close to New Melle.
Washington
Kirkwood
Hermann
Gateway Transportation Center
Flight Path Map
This map shows the direct air route between Union and Saint Peters. Straight-line distance: 31.8 mi (51.17 km).
#1 Union
City in and county seat of Franklin County, Missouri, United States
| Population | 12,094 |
| Coordinates | 38.4500500, -91.0084800 |
| Altitude | 162 |
| Country | United States |
#2 Saint Peters
The most populous city in St.
| Population | 58,043 |
| Coordinates | 38.8003300, -90.6265100 |
| Altitude | 134 |
| Country | United States |
End: I 70 West (-90.626511, 38.800311)
Estimated Travel Time
Distance: 75 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 33m |
| 40 mph (64.37 km/h) | 01h 09m |
| 50 mph (80.47 km/h) | 00h 55m |
| 60 mph (96.56 km/h) | 00h 46m |
| 70 mph (112.65 km/h) | 00h 39m |
| 80 mph (129 km/h) | 00h 34m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $6.18 | $12.37 |
| Mid-grade | $4.25 | $6.97 | $13.95 |
| Premium | $4.65 | $7.63 | $15.27 |
| Diesel | $5.30 | $8.70 | $17.40 |
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 Missouri · May 02, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.