The fair place to meet is San Antonio, TX — the city closest to the midpoint of Miami and San Diego. From the farther side that’s about 24 hr 4 min of driving.
Recommended midpoint
San Antonio, TX
From Miami
24 hr 4 min
1,148 mi to San Antonio
From San Diego
23 hr 37 min
1,126 mi to San Antonio
San Diego has the shorter trip; the split is off by about 27 min. The alternatives below can even it out. Miami and San Diego are about 2,268 miles apart.
Miami and San Diego are about 2,268 miles apart by road. Split the difference and you arrive near San Antonio, the city closest to the halfway point between them. That puts roughly 24 hr 4 min of driving on the Miami side and 23 hr 37 min on the San Diego side — the fairest single meeting point among the cities near the middle.
Over this distance most people will fly rather than drive the whole way. San Antonio still makes a fair, central place for Miami and San Diego to converge, splitting the travel instead of asking one side to cross the country.
If San Antonio doesn't have what you're after, Austin and Houston are also close to the midpoint and worth a look — each keeps the drive reasonably balanced between Miami and San Diego.
San Antonio is a city in the U.S. state of Texas. It is the seventh-most populous city in the United States, the second-most populous city in Texas, and the second-most populous city in the Southern U.S., with a population of 1.43 million at the 2020 census. Read more →
Miami is a coastal city in the U.S. state of Florida. It is the second-most populous city proper in Florida, with a population of 442,241 at the 2020 census. Read more →
San Diego is a city on the Pacific coast of Southern California, adjacent to the Mexico–United States border. It is the eighth-most populous city in the U.S. Read more →
City descriptions adapted from Wikipedia (CC BY-SA); photos via Wikimedia Commons, credited above.
Estimates use straight-line distance and typical road speeds; real drive times vary with route and traffic.