Miles between Ontario, CA and San Marcos, TX

There are
1,338 mi
from Ontario, CA to San Marcos, TX

That's the driving distance. It would take 22 hours 59 mins to go from Ontario, California to San Marcos, Texas.

The flight distance (direct flight from Ontario, CA to San Marcos, TX) is 1,188.66 mi.

1,338 mi = 1.61 kms