The flight distance from Seattle-Tacoma International Airport (SEA) in Seattle, United States to Sofia Airport (SOF) in Sofia, Bulgaria is 9,440 kilometers (5,866 miles / 5,097 nautical miles). The estimated flight time for this route is approximately 12h, flying north northeast at a heading of 25°.

This is an ultra-long-haul route, one of the longest in aviation. It requires wide-body aircraft with extended range capability such as the Airbus A350-900ULR or Boeing 777-200LR. Passengers should prepare for an extended flight with multiple meal services.

This is an international route connecting United States with Bulgaria. It is an intercontinental flight between North America and Europe. Travelers should check visa requirements, customs regulations, and any travel advisories before booking.

Time zone information: When it's 21:56 in Seattle, it's 07:56 in Sofia. With a 10-hour time difference, travelers should plan for significant jet lag. It typically takes one day per hour of time difference to fully adjust.

There is a significant elevation difference of 1,310 feet between the two airports. Sofia Airport sits higher than Seattle-Tacoma International Airport.

The return flight from Sofia (SOF) to Seattle (SEA) follows a heading of 338° (north northwest). Actual flight times may vary depending on wind conditions, air traffic, and the specific aircraft used.

For more information about these airports, visit the Seattle-Tacoma International Airport (SEA) and Sofia Airport (SOF) detail pages, or use our flight duration calculator to compare other routes.