How far is Karnes City, TX from San Antonio, TX?
The driving distance from Karnes City, TX to San Antonio, TX is about 54.1 miles (87 km), with a travel time of about 01h 02m by car.
- The straight-line flight distance is about 51.6 miles (83.1 km).
- For a round trip, plan for roughly 02h 05m 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 01h 02m.
A morning start gives you useful time at the destination and keeps the return out of the late evening.
This departure sits inside the recommended comfort window for the route.
Halfway Point
A useful midpoint for breaks, coffee, or meeting in the middle.
City in Texas, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Partly Sunny
Mostly Cloudy
Driving Route Map
The map below follows the saved road route between Karnes City and San Antonio.
Turn-by-Turn Driving Directions
Step-by-step road directions between Karnes City and San Antonio.
-
1
Start on East Calvert Avenue
3177 ft · 1 min · East Calvert Avenue
-
2
Turn right onto North US Highway 181
8.7 mi · 10 min · North US Highway 181
-
3
Continue on Front Street
1.3 mi · 2 min · Front Street
-
4
Continue on North US Highway 181
5.7 mi · 7 min · North US Highway 181
-
5
Continue on South Storts Street
2 mi · 2 min · South Storts Street
-
6
Continue on US Highway 181 South
4.4 mi · 5 min · US Highway 181 South
-
7
Continue on 10th Street
3.6 mi · 4 min · 10th Street
-
8
Continue on US Highway 181 North
16.6 mi · 20 min · US Highway 181 North
-
9
Take the exit straight toward South US Highway 181
2785 ft · 34 sec · South US Highway 181
-
10
Merge slight left
9.2 mi · 10 min
-
11
Take the exit slight right toward Commerce Street, Downtown, The Alamo
1358 ft · 33 sec
-
12
Turn straight onto Interstate 37 South
116 m · 12 sec · Interstate 37 South
-
13
Turn left onto East Commerce Street
1.4 km · 2 min · East Commerce Street
-
14
Turn left onto Military Plaza
119 m · 16 sec · Military Plaza
-
15
Turn left onto Dolorosa Street
100 m · 8 sec · Dolorosa Street
-
16
Arrive at your destination
0 m · 1 sec · Dolorosa Street
Car Route Details
A richer read on the saved driving route between Karnes City and San Antonio.
Highway-focused drive
Most of the mileage stays on named highways, so the important moments are ramps, exits, merges, and the final local approach.
US Highway 181 North
Continue on US Highway 181 North
16.6 mi · 00h 20m
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.
Partly Sunny leaving Karnes City and Mostly Cloudy near San Antonio.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Karnes City to San Antonio?
The road trip is about 54.1 miles (87 km) and usually takes 01h 02m 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?
Floresville is a useful midpoint, sitting about 27 miles from Karnes City and 27 miles from San Antonio.
How much longer is the road route than the straight-line distance?
The direct path is about 51.6 miles (83.1 km), while the road route adds roughly 2.5 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 4:24 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $7.22 one way or $14.44 round trip. Estimated CO2 is about 17 kg one way.
What should you check before leaving?
Before you leave, expect Partly Sunny around Karnes City and Mostly Cloudy near San Antonio.
Stop Ideas Near Floresville
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 Floresville.
San Antonio Station
San Marcos Station
Flight Path Map
This map shows the direct air route between Karnes City and San Antonio. Straight-line distance: 51.64 mi (83.11 km).
#1 Karnes City
City in Karnes County, Texas, United States
| Population | 3,383 |
| Coordinates | 28.8849800, -97.9008400 |
| Altitude | 131 |
| 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: 87 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 48m |
| 40 mph (64.37 km/h) | 01h 21m |
| 50 mph (80.47 km/h) | 01h 04m |
| 60 mph (96.56 km/h) | 00h 54m |
| 70 mph (112.65 km/h) | 00h 46m |
| 80 mph (129 km/h) | 00h 40m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.78 | $7.22 | $14.44 |
| Mid-grade | $4.25 | $8.12 | $16.24 |
| Premium | $4.59 | $8.77 | $17.54 |
| Diesel | $3.99 | $7.63 | $15.25 |
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 17, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.