How far is Austin, TX from San Marcos, TX?
The driving distance from Austin, TX to San Marcos, TX is about 30.8 miles (49.5 km), with a travel time of about 00h 36m by car.
- The straight-line flight distance is about 29.1 miles (46.8 km).
- For a round trip, plan for roughly 01h 13m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 7:00 AM to 7:00 PM CDT.
Reverse, save, or send this route
This is an easy same-day return drive. Copy the route link, send it to another device, or print a clean version before you head out.
This is an easy same-day return drive.
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 36m.
This is a short drive, so your comfort window is wide. Traffic and current weather matter more than the clock.
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 Hays 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 Austin and San Marcos.
Turn-by-Turn Driving Directions
Step-by-step road directions between Austin and San Marcos.
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1
Start on East 5th Street
2551 ft · 1 min · East 5th Street
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2
At the end of the road, turn right onto North Interstate 35
1893 ft · 40 sec · North Interstate 35
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3
Take the ramp slight left toward I 35 South
899 ft · 22 sec
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4
Merge slight left onto Purple Heart Trail
27.6 mi · 30 min · Purple Heart Trail
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5
Take the exit slight right toward TX 80 East, TX 142 East, TX 21 East: Bastrop, Luling
1079 ft · 26 sec
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6
Turn straight onto North Interstate 35
3250 ft · 1 min · North Interstate 35
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7
Turn slight right
144 m · 17 sec
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8
Turn slight right onto East Hopkins Street
1.1 mi · 2 min · East Hopkins Street
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9
Turn right onto North LBJ Drive
64 m · 9 sec · North LBJ Drive
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10
Turn left
128 m · 36 sec
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11
At the end of the road, turn left onto North Guadalupe Street
43 m · 3 sec · North Guadalupe Street
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12
Arrive at your destination
0 m · 1 sec · North Guadalupe Street
Car Route Details
A richer read on the saved driving route between Austin and San Marcos.
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
27.6 mi · 00h 30m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A short regional drive
This route is short enough to handle as a quick errand, commute, or easy same-day return without much planning overhead.
Partly Sunny leaving Austin and Partly Sunny near San Marcos.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Austin to San Marcos?
The road trip is about 30.8 miles (49.5 km) and usually takes 00h 36m in normal driving conditions.
Is this a same-day trip or an overnight route?
This route is short enough to handle as a quick errand, commute, or easy same-day return without much planning overhead.
What is the halfway point on this route?
Buda is a useful midpoint, sitting about 15.4 miles from Austin and 15.3 miles from San Marcos.
How much longer is the road route than the straight-line distance?
The direct path is about 29.1 miles (46.8 km), while the road route adds roughly 1.7 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 7:00 AM to 7:00 PM CDT. If you want a more comfortable same-day return, try to leave by 7:16 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $4.12 one way or $8.24 round trip. Estimated CO2 is about 9.7 kg one way.
What should you check before leaving?
Before you leave, expect Partly Sunny around Austin and Partly Sunny near San Marcos.
Stop Ideas Near Buda
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 Buda.
Austin
San Marcos Station
Taylor
San Antonio Station
Flight Path Map
This map shows the direct air route between Austin and San Marcos. Straight-line distance: 29.06 mi (46.76 km).
#1 Austin
The eleventh most populous city in the United States and the center of the Austin metropolitan area.
| Population | 995,484 |
| Coordinates | 30.2671500, -97.7430600 |
| Altitude | 149 |
| Country | United States |
#2 San Marcos
The most populous city in Hays County, Texas.
| Population | 66,350 |
| Coordinates | 29.8832700, -97.9413900 |
| Altitude | 188 |
| Country | United States |
End: San Marcos (-97.94139, 29.88327)
Estimated Travel Time
Distance: 50 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 01m |
| 40 mph (64.37 km/h) | 00h 46m |
| 50 mph (80.47 km/h) | 00h 36m |
| 60 mph (96.56 km/h) | 00h 30m |
| 70 mph (112.65 km/h) | 00h 26m |
| 80 mph (129 km/h) | 00h 23m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.78 | $4.12 | $8.24 |
| Mid-grade | $4.25 | $4.63 | $9.27 |
| Premium | $4.59 | $5.00 | $10.01 |
| Diesel | $3.99 | $4.35 | $8.70 |
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 · Apr 18, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.