There are
694 mi
from Layton, UT to Monrovia, CA
That's the driving distance. It would take 12 hours 3 mins to go from Layton, Utah to Monrovia, California.
The flight distance (direct flight from Layton, UT to Monrovia, CA) is 580.45 mi.
694 mi = 1,116.27 kms