The flight distance from Chiang Rai International Airport (CEI) in Chiang Rai, Thailand to St Louis Lambert International Airport (STL) in St Louis, United States is 13,401 kilometers (8,327 miles / 7,236 nautical miles). The estimated flight time for this route is approximately 17h, flying north at a heading of 9°.

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 Thailand with United States. It is an intercontinental flight between Asia and North America. Travelers should check visa requirements, customs regulations, and any travel advisories before booking.

Time zone information: When it's 03:56 in Chiang Rai, it's 14:56 in St Louis. With a 13-hour time difference, travelers should plan for significant jet lag. It typically takes one day per hour of time difference to fully adjust.

The return flight from St Louis (STL) to Chiang Rai (CEI) follows a heading of 349° (north). Actual flight times may vary depending on wind conditions, air traffic, and the specific aircraft used.

For more information about these airports, visit the Chiang Rai International Airport (CEI) and St Louis Lambert International Airport (STL) detail pages, or use our flight duration calculator to compare other routes.