How far is Dayton, OH from Saint Marys, OH?
The driving distance from Dayton, OH to Saint Marys, OH is about 62 miles (99.8 km), with a travel time of about 01h 20m by car.
- The straight-line flight distance is about 55.1 miles (88.7 km).
- For a round trip, plan for roughly 02h 40m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 8:00 AM to 10:00 AM EDT.
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 01h 20m.
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.
Village in Shelby County, Ohio
Route Weather Snapshot
Check the forecast at both ends before you head out.
Chance Rain Showers
Driving Route Map
The map below follows the saved road route between Dayton and Saint Marys.
Turn-by-Turn Driving Directions
Step-by-step road directions between Dayton and Saint Marys.
-
1
Start on South Main Street
1.3 km · 2 min · South Main Street
-
2
Take the ramp right toward I 75 North, SR 4 North: Toledo, Springfield
43 m · 3 sec
-
3
Keep slight left to continue on I 75 North: Toledo
1458 ft · 36 sec
-
4
Merge slight left
38.8 mi · 43 min
-
5
Take the exit slight right toward SR 29: Saint Marys, Sidney
1338 ft · 36 sec
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6
Turn left onto Saint Marys Avenue
11.8 mi · 16 min · Saint Marys Avenue
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7
Turn right
8.9 mi · 16 min
-
8
At the end of the road, turn left onto East Spring Street
1.2 mi · 2 min · East Spring Street
-
9
Turn left onto South Front Street
32 m · 5 sec · South Front Street
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10
Arrive at your destination
0 m · 1 sec · South Front Street
Car Route Details
A richer read on the saved driving route between Dayton and Saint Marys.
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 75 North
Merge slight left
38.8 mi · 00h 43m
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 Dayton and Chance Rain Showers near Saint Marys.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Dayton to Saint Marys?
The road trip is about 62 miles (99.8 km) and usually takes 01h 20m 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?
Lockington is a useful midpoint, sitting about 31 miles from Dayton and 31 miles from Saint Marys.
How much longer is the road route than the straight-line distance?
The direct path is about 55.1 miles (88.7 km), while the road route adds roughly 6.9 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 EDT. If you want a more comfortable same-day return, try to leave by 3:50 PM EDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $8.11 one way or $16.23 round trip. Estimated CO2 is about 19.5 kg one way.
What should you check before leaving?
Before you leave, expect Sunny around Dayton and Chance Rain Showers near Saint Marys.
Stop Ideas Near Lockington
Useful break, food, and waypoint ideas within about 15 miles of the route midpoint.
The Inn at Versailles
Troy Director of Public Services
The Solid Rock Apostolic Church
Transit and Meeting Points
Useful pickup, handoff, or rendezvous points close to Lockington.
Connersville station
Columbus, OH
Flight Path Map
This map shows the direct air route between Dayton and Saint Marys. Straight-line distance: 55.12 mi (88.71 km).
#1 Dayton
The ninth most populous city in Ohio.
| Population | 139,907 |
| Coordinates | 39.7589500, -84.1916100 |
| Altitude | 225 |
| Country | United States |
#2 Saint Marys
City in Ohio, United States
| Population | 8,113 |
| Coordinates | 40.5422700, -84.3894000 |
| Altitude | 264 |
| Country | United States |
End: Saint Marys (-84.3894, 40.54227)
Estimated Travel Time
Distance: 100 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 02h 03m |
| 40 mph (64.37 km/h) | 01h 33m |
| 50 mph (80.47 km/h) | 01h 14m |
| 60 mph (96.56 km/h) | 01h 02m |
| 70 mph (112.65 km/h) | 00h 53m |
| 80 mph (129 km/h) | 00h 46m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.71 | $8.11 | $16.23 |
| Mid-grade | $4.24 | $9.29 | $18.58 |
| Premium | $4.79 | $10.49 | $20.98 |
| Diesel | $4.30 | $9.43 | $18.85 |
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 Ohio · Apr 19, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.