There are
2,707 mi
from Simi Valley, CA to Greenbelt, MD
That's the driving distance. It would take 2 days to go from Simi Valley, California to Greenbelt, Maryland.
The flight distance (direct flight from Simi Valley, CA to Greenbelt, MD) is 2,325.66 mi.
2,707 mi = 3.22 kms