There are
1,515 mi
from Katy, TX to Downey, CA
That's the driving distance. It would take 1 day 1 hour to go from Katy, Texas to Downey, California.
The flight distance (direct flight from Katy, TX to Downey, CA) is 1,337.33 mi.
1,515 mi = 2,438.87 kms