How far is San Marcos, TX from San Antonio, TX?
The driving distance from San Marcos, TX to San Antonio, TX is about 49.9 miles (80.3 km), with a travel time of about 00h 52m by car.
- The straight-line flight distance is about 45.9 miles (73.9 km).
- For a round trip, plan for roughly 01h 44m 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 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.
City in Guadalupe County, Texas, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Partly Sunny
Driving Route Map
The map below follows the saved road route between San Marcos and San Antonio.
Turn-by-Turn Driving Directions
Step-by-step road directions between San Marcos and San Antonio.
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1
Start on North Guadalupe Street
1.5 km · 2 min · North Guadalupe Street
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2
Turn right onto South Interstate 35
3256 ft · 1 min · South Interstate 35
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3
Take the ramp straight toward I 35 South
932 ft · 23 sec
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4
Merge slight left onto Purple Heart Trail
15.8 mi · 17 min · Purple Heart Trail
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5
Continue on Interstate Highway 35
1.7 mi · 2 min · Interstate Highway 35
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6
Continue on Purple Heart Trail
11.9 mi · 13 min · Purple Heart Trail
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7
Continue on North Pan Am Expressway
10 mi · 12 min · North Pan Am Expressway
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8
Keep slight left to continue on North Pan Am Expressway
6.4 mi · 8 min · North Pan Am Expressway
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9
Keep slight left to continue on North Pan Am Expressway
2907 ft · 41 sec · North Pan Am Expressway
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10
Take the exit slight right toward Lexington Avenue, Main Avenue, San Pedro Avenue
684 ft · 17 sec
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11
Turn straight onto East Elmira Street
526 ft · 17 sec · East Elmira Street
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12
Turn left onto North Main Avenue
830 ft · 19 sec · North Main Avenue
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13
Enter the roundabout and take exit 2 toward Navarro Street
49 m · 3 sec · Navarro Street
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14
Exit the roundabout onto Navarro Street
34 m · 2 sec · Navarro Street
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15
Keep slight right to continue on North Main Avenue
2181 ft · 52 sec · North Main Avenue
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16
Turn right onto West Travis Street
68 m · 11 sec · West Travis Street
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17
Turn left onto North Flores Street
807 ft · 20 sec · North Flores Street
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18
Continue on Military Plaza
119 m · 16 sec · Military Plaza
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19
Turn left onto Dolorosa Street
100 m · 8 sec · Dolorosa Street
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20
Arrive at your destination
0 m · 1 sec · Dolorosa Street
Car Route Details
A richer read on the saved driving route between San Marcos and San Antonio.
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.
Purple Heart Trail
Merge slight left onto Purple Heart Trail
15.8 mi · 00h 17m
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 San Marcos and Partly Sunny near San Antonio.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from San Marcos to San Antonio?
The road trip is about 49.9 miles (80.3 km) and usually takes 00h 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?
Cibolo is a useful midpoint, sitting about 24.7 miles from San Marcos and 25.2 miles from San Antonio.
How much longer is the road route than the straight-line distance?
The direct path is about 45.9 miles (73.9 km), while the road route adds roughly 4 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 4:46 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $6.65 one way or $13.30 round trip. Estimated CO2 is about 15.6 kg one way.
What should you check before leaving?
Before you leave, expect Sunny around San Marcos and Partly Sunny near San Antonio.
Stop Ideas Near Cibolo
Useful break, food, and waypoint ideas within about 15 miles of the route midpoint.
New Braunfels Parks and Recreation
Schertz EMS
Windcrest City Hall
Comal County Courthouse(Gerichtsgebäude)
Transit and Meeting Points
Useful pickup, handoff, or rendezvous points close to Cibolo.
San Antonio Station
San Marcos Station
Austin
Flight Path Map
This map shows the direct air route between San Marcos and San Antonio. Straight-line distance: 45.89 mi (73.85 km).
#1 San Marcos
The most populous city in Hays County, Texas.
| Population | 66,350 |
| Coordinates | 29.8832700, -97.9413900 |
| Altitude | 188 |
| Country | United States |
#2 San Antonio
The seventh most populous city in the United States and the center of the San Antonio metropolitan area.
| Population | 1,567,118 |
| Coordinates | 29.4241200, -98.4936300 |
| Altitude | 198 |
| Country | United States |
End: Dolorosa Street (-98.493645, 29.424163)
Estimated Travel Time
Distance: 80 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 39m |
| 40 mph (64.37 km/h) | 01h 14m |
| 50 mph (80.47 km/h) | 00h 59m |
| 60 mph (96.56 km/h) | 00h 49m |
| 70 mph (112.65 km/h) | 00h 42m |
| 80 mph (129 km/h) | 00h 37m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.78 | $6.65 | $13.30 |
| Mid-grade | $4.25 | $7.48 | $14.97 |
| Premium | $4.59 | $8.08 | $16.16 |
| Diesel | $3.99 | $7.03 | $14.06 |
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 Texas · Jun 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.