It is 388.71 miles accrding to MapQuest.
Austin TX is about 350 miles due south of Oklahoma City,OK.
north
Austin TX is practically due south of Oklahoma City OK.
It is approximately 220 miles from Pampa, TX to Oklahoma City, Oklahoma.
Almost due South.
389 miles
Using I-35 S, about 400 miles
It is 388.71 miles according to MapQuest.
About 6-1/2 hours
It is 459 miles
Take I-35 about 380 miles north
That is a far piece of Texas that is best called 700 miles south of Oklahoma City.