Kadena Air Base to Austin Bergstrom International Airport
Approx. 12084 km - about 13h 30m in the air and 14h 48m total from gate to gate, at an average speed around 894 km/h.
Real-world flights on routes this long almost always include at least one stop. Use this nonstop estimate as a guide, and allow extra time for connections and layovers when planning your trip.