How far is San Marcos, TX from Brownsville, TX?
The driving distance from San Marcos, TX to Brownsville, TX is about 320.1 miles (515.2 km), with a travel time of about 05h 44m by car.
- The straight-line flight distance is about 276.4 miles (444.9 km).
- For a round trip, plan for roughly 11h 29m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 6:00 AM to 8:00 AM CDT.
Reverse, save, or send this route
This drive is better planned with a longer stop or an overnight stay. Copy the route link, send it to another device, or print a clean version before you head out.
This drive is better planned with a longer stop or an overnight stay.
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 05h 44m.
An early departure helps you fit a real stop into the day without turning the return into a late-night drive.
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 San Patricio County, Texas, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Partly Cloudy
Driving Route Map
The map below follows the saved road route between San Marcos and Brownsville.
Turn-by-Turn Driving Directions
Step-by-step road directions between San Marcos and Brownsville.
-
1
Start on North Guadalupe Street
1.5 km · 2 min · North Guadalupe Street
-
2
Turn right onto South Interstate 35
3256 ft · 1 min · South Interstate 35
-
3
Take the ramp straight toward I 35 South
932 ft · 23 sec
-
4
Merge slight left onto Purple Heart Trail
15.8 mi · 17 min · Purple Heart Trail
-
5
Continue on Interstate Highway 35
1.7 mi · 2 min · Interstate Highway 35
-
6
Continue on Purple Heart Trail
11.9 mi · 13 min · Purple Heart Trail
-
7
Continue on North Pan Am Expressway
10 mi · 12 min · North Pan Am Expressway
-
8
Keep slight right to continue on Connally Loop
11 mi · 12 min · Connally Loop
-
9
Take the exit slight right toward I 37, US 281 North: San Antonio, Corpus Christi
1184 ft · 29 sec
-
10
Keep slight left to continue on I 37 South: Corpus Christi
2457 ft · 1 min
-
11
Merge slight left
118.7 mi · 1 hr 59 min
-
12
Take the exit slight right toward I 69E, US 77: Kingsville, Brownsville
31.3 mi · 34 min
-
13
Keep slight left to continue on U.S. Highway 77
61.3 mi · 1 hr 9 min · U.S. Highway 77
-
14
Keep slight left to continue on U.S. Highway 77
43.7 mi · 47 min · U.S. Highway 77
-
15
Continue on North Expressway
2.1 mi · 2 min · North Expressway
-
16
Keep slight left to continue on North Expressway
9 mi · 10 min · North Expressway
-
17
Take the exit slight right toward 12th-14th Street
1730 ft · 42 sec
-
18
Turn straight onto South Expressway
101 m · 9 sec · South Expressway
-
19
Turn right onto East 12th Street
1.2 km · 2 min · East 12th Street
-
20
Turn right onto East Washington Street
9 m · 1 sec · East Washington Street
-
21
Arrive at your destination
0 m · 1 sec · East Washington Street
Car Route Details
A richer read on the saved driving route between San Marcos and Brownsville.
Long-distance drive
This route is long enough that fuel, rest stops, weather, and timing matter more than any single maneuver.
I 37 South
Merge slight left
119 mi · 01h 59m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A longer out-and-back drive
This is still possible in one day, but it becomes a long driving day. Leaving early and planning your stop window matters more here.
Sunny leaving San Marcos and Partly Cloudy near Brownsville.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from San Marcos to Brownsville?
The road trip is about 320.1 miles (515.2 km) and usually takes 05h 44m in normal driving conditions.
Is this a same-day trip or an overnight route?
This is still possible in one day, but it becomes a long driving day. Leaving early and planning your stop window matters more here.
What is the halfway point on this route?
San Patricio is a useful midpoint, sitting about 160.4 miles from San Marcos and 159.7 miles from Brownsville.
How much longer is the road route than the straight-line distance?
The direct path is about 276.4 miles (444.9 km), while the road route adds roughly 43.7 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 6:00 AM to 8:00 AM CDT. If you want a more comfortable same-day return, try to leave by 5:30 AM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $42.70 one way or $85.41 round trip. Estimated CO2 is about 100.4 kg one way.
What should you check before leaving?
Before you leave, expect Sunny around San Marcos and Partly Cloudy near Brownsville.
Flight Path Map
This map shows the direct air route between San Marcos and Brownsville. Straight-line distance: 276.43 mi (444.87 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 Brownsville
The southernmost city in Texas.
| Population | 183,428 |
| Coordinates | 25.9017500, -97.4974800 |
| Altitude | 10 |
| Country | United States |
End: Brownsville (-97.49748, 25.90175)
Estimated Travel Time
Distance: 515 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 10h 39m |
| 40 mph (64.37 km/h) | 08h 00m |
| 50 mph (80.47 km/h) | 06h 24m |
| 60 mph (96.56 km/h) | 05h 20m |
| 70 mph (112.65 km/h) | 04h 34m |
| 80 mph (129 km/h) | 03h 59m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.78 | $42.70 | $85.41 |
| Mid-grade | $4.25 | $48.05 | $96.10 |
| Premium | $4.59 | $51.88 | $103.76 |
| Diesel | $3.99 | $45.12 | $90.24 |
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.