There are
2,483 mi
from Downey, CA to Johnstown, PA
That's the driving distance. It would take 1 day 20 hours to go from Downey, California to Johnstown, Pennsylvania.
The flight distance (direct flight from Downey, CA to Johnstown, PA) is 2,186.01 mi.
2,483 mi = 3,996.47 kms