Origin
Karnes City, TX
Afternoon in Karnes City on Sunday
Local time
2:07 PM
CDT
Current temp
64°F
Unavailable
Live forecast
Trip from Karnes City, TX to San Antonio, TX
Compiled and reviewed by the US Trip Planner planning team at COD Solutions Oy · Last reviewed Apr 19, 2026 · Editorial standards
Drive Time
1h 4m
Distance
54 mi
87 km
Drive Score
7/10
Good drive
Same Day?
Yes, doable
Fuel Cost
$8
one way
EV Charging
Unknown
Best Time to Leave
4 AM
0h 59m
★
6 AM
1h 4m
8 AM
1h 14m
10 AM
1h 8m
12 PM
1h 7m
3 PM
1h 8m
5 PM
1h 14m
8 PM
1h 1m
Estimated drive times based on typical traffic patterns. Actual times may vary with weather, construction, and real-time conditions.
Karnes City, TX
Wikimedia Commons
San Antonio, TX
Wikimedia Commons
Trip Overview
This straightforward 54-mile drive from Karnes City, TX, to San Antonio, TX, will take you about 1 hour and 4 minutes. It's a perfect day trip, easily manageable in a single go, with a modest estimated fuel cost of $8. The route is primarily highway-focused, meaning you'll spend most of your time on major roads. Both Karnes City and San Antonio are situated within the Great Plains region, so you won't experience a significant change in landscape. This drive is ideal for those looking for a quick and efficient journey between these two Texas locations.
Main Roads
| Road | Distance | Duration |
|---|---|---|
| US Highway 181 North | 16.6 mi | 19m |
| North US Highway 181 | 14.5 mi | 16m |
| I 37 | 9.2 mi | 10m |
| US Highway 181 South | 4.4 mi | 4m |
| 10th Street | 3.6 mi | 4m |
| South Storts Street | 2 mi | 2m |
| Front Street | 1.3 mi | 1m |
| East Commerce Street | 0.9 mi | 1m |
Longest stretch:
US Highway 181 North
— 16.6 mi, about 19m
Turn-by-Turn Driving Directions
Step-by-step road directions between Karnes City, TX and San Antonio, TX.
1
Start on US 181 Business
0.6 mi
·
1 min
·
East Calvert Avenue
2
Turn right onto US 181
8.7 mi
·
9 min
·
North US Highway 181
3
Continue on US 181
1.3 mi
·
1 min
·
Front Street
4
Continue on US 181; FM 887
5.7 mi
·
6 min
·
North US Highway 181
5
Continue on US 181
2.0 mi
·
2 min
·
South Storts Street
6
Continue on US 181
4.4 mi
·
4 min
·
US Highway 181 South
7
Continue on US 181
3.6 mi
·
4 min
·
10th Street
8
Continue on US 181
17 mi
·
19 min
·
US Highway 181 North
9
Take the exit onto US 181
0.5 mi
·
33 sec
·
South US Highway 181
10
Merge onto I 37
9.2 mi
·
10 min
·
I 37
Use the straight / slight right lanes.
11
Take the exit
0.3 mi
·
33 sec
Exit 141
Toward Commerce Street, Downtown, The Alamo
Use the straight / slight right lanes.
12
Turn straight onto Interstate 37 South
380 ft
·
11 sec
·
Interstate 37 South
13
Turn left onto East Commerce Street
0.9 mi
·
1 min
·
East Commerce Street
14
Turn left onto Military Plaza
392 ft
·
15 sec
·
Military Plaza
15
Turn left onto Dolorosa Street
327 ft
·
8 sec
·
Dolorosa Street
16
Arrive at destination
Dolorosa Street
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Mid-route town
Meal stop
27 mi into the route
Best for: Lunch, fuel, and a longer reset
This sits close to the middle of the route, so it works well for the longest stop of the day.
Pacing Suggestions
Fuel and coffee
A short stop after about 12 miles helps settle the day before fatigue starts building.
Meal break
The midpoint is around 27 miles from Karnes City, TX, which is a good place for a longer meal and fuel stop.
These stop ideas are pacing suggestions — the exact town or exit can change with traffic, hotel plans, and fuel range.
Heads-up: tricky spots
5 of 65 decision points cluster between mile 0.6 and 54 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
3
0.6 mi into trip
|
~1m in
|
US 181 / North US Highway 181
Turn right onto US 181 / North US Highway 181
Navigation decision point
3
43 mi into trip
|
~50m in
|
US 181 / South US Highway 181
Take the exit onto US 181 / South US Highway 181
Exit ramp - move to the correct lane early
5
43.5 mi into trip
|
~50m in
|
I 37
Merge onto I 37
Merge point - match speed before joining. Lane positioning matters here
Use the straight / slight right lanes.
8
52.7 mi into trip
|
~1h 1m in
Take the exit toward Commerce Street, Downtown, The Alamo
Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one
Use the straight / slight right lanes.
Exit 141
Toward Commerce Street, Downtown, The Alamo
5
54 mi into trip
|
~1h 3m in
|
Dolorosa Street
Turn left onto Dolorosa Street
Navigation decision point
Fuel & Cost
Regular Gas
$8.16 one way
$16.32 round trip
$3.84/gal
25.4 MPG avg
19 kg CO2
| Fuel Type | $/gal | One Way | Round Trip |
|---|---|---|---|
| midgrade | $4.20 | $8.93 | $17.86 |
| premium | $4.54 | $9.64 | $19.28 |
| diesel | $5.61 | $11.92 | $23.85 |
No toll roads detected on this route.
Drive Cost (one way)
Fuel
$8
Estimated CO2 emission: 18.9 kg one way. Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $6 in charging · 0 stops · 68% less CO2
| Vehicle Type | kWh | Stops | DC Fast | Home Charge |
|---|---|---|---|---|
| Average EV | 16.2 | 0 | $5.67 | $2.59 |
| Efficient EV | 13.5 | 0 | $4.73 | $2.16 |
| EV Truck/SUV | 21.6 | 0 | $7.56 | $3.46 |
Gas CO2
19 kg
EV CO2
6 kg (68% less)
This trip is well within single-charge range for most EVs. No charging stops needed if you start fully charged.
DC fast charging avg $0.35/kWh. Home charging avg $0.16/kWh. US grid CO2: 0.39 kg/kWh.
Travel Intel
Current conditions at both ends of the drive.
Destination
San Antonio, TX
Afternoon in San Antonio on Sunday
Local time
2:07 PM
CDT
Current temp
68°F
Mostly Cloudy
SSE 5 to 15 mph
1% chance
Live forecast
High Wind Warning
High Wind Warning issued April 17 at 9:08PM MDT until April 18 at 12:00PM MDT by NWS Midland/Odessa TX
Wind Advisory
Wind Advisory issued April 17 at 9:08PM MDT until April 18 at 9:00AM MDT by NWS Midland/Odessa TX
Time zone
Same local time
Origin and destination are on the same clock, so arrival timing is easier to judge at a glance.
Temperature spread
4 degrees warmer at arrival
A meaningful temperature swing is a good cue to rethink layers, water, and how soon you want to arrive.
Road read
1h 4m on the road
The weather snapshot is not static. If you are leaving later, give both cities one more quick forecast check before departure.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
What kind of drive is this?
Expect a highway-focused drive for the majority of this trip, with 84% of the journey on major roadways like US Highway 181 North and I-37. You'll encounter one continuous stretch of 16.6 miles on US Highway 181 North, offering a consistent pace. This route is designed for efficiency, minimizing time spent on slower local roads. The road character remains largely consistent, prioritizing a direct path toward your destination.
84% highway — fuel and pacing are the main things to plan.
16 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 16.6 mi on US Highway 181 North.
How Hard Is This Drive?
2/10
This is a straightforward highway drive that stays mostly on US Highway 181 North and North US Highway 181. Navigation is very simple - set it and forget it for most of the drive. The trickiest moment comes around 0.6 miles in near US 181 / North US Highway 181.
Driving Effort
2/10
Very easy - short and simple to drive
Balances navigation complexity with total wheel time.
The drive from Karnes City, TX to San Antonio, TX is easy. At 1h 4m with 84% highway, most drivers will find it relaxed and low-stress.
Where does it get tricky?
The main spots that need attention: at 0.6 miles (US 181 / North US Highway 181): Navigation decision point; at 43 miles (US 181 / South US Highway 181): Exit ramp - move to the correct lane early; at 43.5 miles (I 37): Merge point - match speed before joining. Lane positioning matters here.
About the Cities
Arriving in San Antonio, TX
Full guide →Founded 1718
San Antonio is the second largest city in the state of Texas and the 7th largest in the United States. It's the 24th largest metropolitan area in the country. Visited by more than 31 million annual visitors, San Antonio is a beautiful city at the axis of three different geological terrains: Hill Country, South Texas Plains and Prairie and Lakes. There's a lot to do in this city: fine art museums, historical missions and plenty of amusement parks in addition to great dining and lots of drinking. The culture and people are vibrant and interesting. San Antonio's downtown is one of the most lively in the nation.
Top landmarks
- • Alamo Mission in San Antonio — historic place in San Antonio, Bexar County, Texas
- • San Antonio Missions National Historical Park — historic district in San Antonio, Bexar County, Texas
- • Fort Sam Houston — military base in San Antonio, Texas
City content from Wikivoyage (CC BY-SA 4.0) and Wikidata (CC0).
Who Is This Route For?
Weekend Trip
Doable as a same-day drive at 1h 4m. Total distance: 54 miles.
Family Friendly
Moderate complexity with 0 natural rest stops along the way.
Solo Traveler
1h 4m drive, comfortable solo distance.
EV Driver
0 DC fast chargers along the route. Coverage: unknown.
First-Time Driver
Mostly highway driving (84%). Straightforward navigation.
Frequently Asked Questions
The longest stretch is about 16.6 miles on US Highway 181 North. The full list of main roads is in the Roads section above.
Yes. At under 2 hours behind the wheel, this works well for families — plan one quick stop if you have younger kids.
The main spots that need attention: at 0.6 miles (US 181 / North US Highway 181): Navigation decision point; at 43 miles (US 181 / South US Highway 181): Exit ramp - move to the correct lane early; at 43.5 miles (I 37): Merge point - match speed before joining. Lane positioning matters here.
Yes — San Antonio Missions National Historical Park. See the National Parks section for detour distances and tips on detours.
Yes. A round trip is manageable in a single day if you plan a break at San Antonio, TX before heading back.
How this page is built
Compiled by the US Trip Planner planning team at COD Solutions Oy from open government datasets — OSRM over OpenStreetMap for geometry, EIA for fuel prices, and NPS for national parks. See our methodology for refresh cadence and limitations.
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