How far is Saint Marys, OH from Dayton, OH?
The driving distance from Saint Marys, OH to Dayton, OH is about 69.7 miles (112.1 km), with a travel time of about 01h 06m by car.
- The straight-line flight distance is about 55.1 miles (88.7 km).
- For a round trip, plan for roughly 02h 13m 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 06m.
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 Ohio, United States of America
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 Saint Marys and Dayton.
Turn-by-Turn Driving Directions
Step-by-step road directions between Saint Marys and Dayton.
-
1
Start on South Front Street
32 m · 9 sec · South Front Street
-
2
Turn right onto West Spring Street
1705 ft · 47 sec · West Spring Street
-
3
Turn left onto North Spruce Street
1.1 km · 1 min · North Spruce Street
-
4
Take the ramp slight right
1953 ft · 48 sec
-
5
Merge slight left
10.8 mi · 12 min
-
6
Take the exit slight right toward I 75 South: Dayton
2159 ft · 53 sec
-
7
Merge slight left
55.8 mi · 1 hr 1 min
-
8
Merge slight left
51 m · 2 sec
-
9
Take the exit slight right toward SR 48: Main Street, Grand Avenue
1108 ft · 29 sec
-
10
Turn left onto North Main Street
1.4 km · 2 min · North Main Street
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11
Arrive at your destination
0 m · 1 sec · South Main Street
Car Route Details
A richer read on the saved driving route between Saint Marys and Dayton.
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 South
Merge slight left
55.8 mi · 01h 01m
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.
Chance Rain Showers leaving Saint Marys and Sunny near Dayton.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Saint Marys to Dayton?
The road trip is about 69.7 miles (112.1 km) and usually takes 01h 06m 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?
Kirkwood is a useful midpoint, sitting about 34.8 miles from Saint Marys and 34.9 miles from Dayton.
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 14.6 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 4:16 PM EDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $9.11 one way or $18.23 round trip. Estimated CO2 is about 21.9 kg one way.
What should you check before leaving?
Before you leave, expect Chance Rain Showers around Saint Marys and Sunny near Dayton.
Stop Ideas Near Kirkwood
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 Kirkwood.
Connersville station
Columbus, OH
Flight Path Map
This map shows the direct air route between Saint Marys and Dayton. Straight-line distance: 55.12 mi (88.71 km).
#1 Saint Marys
City in Ohio, United States
| Population | 8,113 |
| Coordinates | 40.5422700, -84.3894000 |
| Altitude | 264 |
| Country | United States |
#2 Dayton
The ninth most populous city in Ohio.
| Population | 139,907 |
| Coordinates | 39.7589500, -84.1916100 |
| Altitude | 225 |
| Country | United States |
End: South Main Street (-84.191655, 39.758942)
Estimated Travel Time
Distance: 112 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 02h 19m |
| 40 mph (64.37 km/h) | 01h 44m |
| 50 mph (80.47 km/h) | 01h 23m |
| 60 mph (96.56 km/h) | 01h 09m |
| 70 mph (112.65 km/h) | 00h 59m |
| 80 mph (129 km/h) | 00h 52m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.71 | $9.11 | $18.23 |
| Mid-grade | $4.24 | $10.44 | $20.87 |
| Premium | $4.79 | $11.78 | $23.57 |
| Diesel | $4.30 | $10.59 | $21.18 |
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.