The fair place to meet is Denver, CO — the city closest to the midpoint of Seattle and Tampa. From the farther side that’s about 31 hr 54 min of driving.
Recommended midpoint
Denver, CO
From Seattle
21 hr 23 min
1,020 mi to Denver
From Tampa
31 hr 54 min
1,521 mi to Denver
Seattle has the shorter trip; the split is off by about 10 hr 31 min. The alternatives below can even it out. Seattle and Tampa are about 2,526 miles apart.
Seattle and Tampa are about 2,526 miles apart by road. Split the difference and you arrive near Denver, the city closest to the halfway point between them. That puts roughly 21 hr 23 min of driving on the Seattle side and 31 hr 54 min on the Tampa 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. Denver still makes a fair, central place for Seattle and Tampa to converge, splitting the travel instead of asking one side to cross the country.
If Denver doesn't have what you're after, Albuquerque and Oklahoma City are also close to the midpoint and worth a look — each keeps the drive reasonably balanced between Seattle and Tampa.
Denver is the capital and most populous city of the U.S. state of Colorado. Officially a consolidated city and county, it is located in the South Platte River valley on the western edge of the High Plains, and is just east of the Front Range of the Rocky… Read more →
Seattle is the most populous city in the U.S. state of Washington and the Pacific Northwest region of North America. Read more →
Tampa is a major city on the Gulf Coast of the U.S. state of Florida and the county seat of Hillsborough County. Tampa's borders include the north shore of Tampa Bay and the east shore of Old Tampa Bay. 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.