There are
2,885 mi
from Wilmington, DE to San Mateo, CA
That's the driving distance. It would take 2 days 2 hours to go from Wilmington, Delaware to San Mateo, California.
The flight distance (direct flight from Wilmington, DE to San Mateo, CA) is 2,499.77 mi.
2,885 mi = 3.22 kms