How far is Saint Charles, MO from Byrnes Mill, MO?
The driving distance from Saint Charles, MO to Byrnes Mill, MO is about 33.6 miles (54 km), with a travel time of about 00h 47m by car.
- The straight-line flight distance is about 24.5 miles (39.5 km).
- For a round trip, plan for roughly 01h 34m 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 47m.
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 Louis County, Missouri, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Mostly Cloudy then Chance Showers And Thunderstorms
Partly Sunny then Chance Rain Showers
Driving Route Map
The map below follows the saved road route between Saint Charles and Byrnes Mill.
Turn-by-Turn Driving Directions
Step-by-step road directions between Saint Charles and Byrnes Mill.
-
1
Start on North Second Street
949 ft · 38 sec · North Second Street
-
2
Turn right onto Jefferson Street
1093 ft · 45 sec · Jefferson Street
-
3
Turn left onto South Fifth Street
1.1 mi · 3 min · South Fifth Street
-
4
Take the ramp slight left toward I 70 East
1019 ft · 14 sec
-
5
Merge slight left
2.7 mi · 3 min
-
6
Take the exit slight right toward I 270: Chicago, Memphis
872 ft · 12 sec
-
7
Keep slight right to continue on I 270 South: Memphis
2339 ft · 33 sec
-
8
Continue on I 270 South: Memphis
723 ft · 10 sec
-
9
Merge slight left
15.6 mi · 19 min
-
10
Take the exit slight right toward MO 30: Gravois Road
1580 ft · 34 sec
-
11
Keep slight right to continue on MO 30 West: Fenton
93 m · 8 sec
-
12
Merge slight left
11.1 mi · 15 min
-
13
Take the exit slight right toward Upper Byrnes Mill Road
33 m · 3 sec
-
14
Turn slight right onto Upper Byrnes Mill Road
1.4 mi · 4 min · Upper Byrnes Mill Road
-
15
Arrive at your destination
0 m · 1 sec · Upper Byrnes Mill Road
Car Route Details
A richer read on the saved driving route between Saint Charles and Byrnes Mill.
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.
I 270 South
Merge slight left
15.6 mi · 00h 19m
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 Cloudy then Chance Showers And Thunderstorms leaving Saint Charles and Partly Sunny then Chance Rain Showers near Byrnes Mill.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Saint Charles to Byrnes Mill?
The road trip is about 33.6 miles (54 km) and usually takes 00h 47m 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?
Des Peres is a useful midpoint, sitting about 16.8 miles from Saint Charles and 16.8 miles from Byrnes Mill.
How much longer is the road route than the straight-line distance?
The direct path is about 24.5 miles (39.5 km), while the road route adds roughly 9.1 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 4:56 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $4.45 one way or $8.90 round trip. Estimated CO2 is about 10.5 kg one way.
What should you check before leaving?
Before you leave, expect Mostly Cloudy then Chance Showers And Thunderstorms around Saint Charles and Partly Sunny then Chance Rain Showers near Byrnes Mill.
Stop Ideas Near Des Peres
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 Des Peres.
Kirkwood
Gateway Transportation Center
Alton
Washington
Flight Path Map
This map shows the direct air route between Saint Charles and Byrnes Mill. Straight-line distance: 24.53 mi (39.47 km).
#1 Saint Charles
A city in St.
| Population | 71,761 |
| Coordinates | 38.7839400, -90.4812300 |
| Altitude | 147 |
| Country | United States |
#2 Byrnes Mill
City in Jefferson County, Missouri, United States
| Population | 3,015 |
| Coordinates | 38.4378300, -90.5817900 |
| Altitude | 143 |
| Country | United States |
End: Byrnes Mill (-90.58179, 38.43783)
Estimated Travel Time
Distance: 54 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 07m |
| 40 mph (64.37 km/h) | 00h 50m |
| 50 mph (80.47 km/h) | 00h 40m |
| 60 mph (96.56 km/h) | 00h 33m |
| 70 mph (112.65 km/h) | 00h 28m |
| 80 mph (129 km/h) | 00h 25m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $4.45 | $8.90 |
| Mid-grade | $4.25 | $5.02 | $10.04 |
| Premium | $4.65 | $5.49 | $10.98 |
| Diesel | $5.30 | $6.26 | $12.52 |
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 · Apr 12, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.