The flight distance from St Louis Regional Airport (ALN) in Alton/St Louis, United States to Denver International Airport (DEN) in Denver, United States is 1,260 kilometers (783 miles / 680 nautical miles). The estimated flight time for this route is approximately 2h, flying west at a heading of 280°.

This is a short-haul route typically served by narrow-body aircraft such as the Boeing 737 or Airbus A320 family. In-flight service is usually limited to drinks and light snacks.

This is a domestic route within United States. Both airports operate in the same country, which may simplify travel requirements and documentation. Despite being a domestic route, there is a 1-hour time difference between the two cities.

Time zone information: When it's 03:59 in Alton/St Louis, it's 02:59 in Denver.

There is a significant elevation difference of 4,890 feet between the two airports. Denver International Airport sits higher than St Louis Regional Airport. Travelers arriving at the higher-elevation airport should be aware of potential altitude effects.

The return flight from Denver (DEN) to Alton/St Louis (ALN) follows a heading of 90° (east). Actual flight times may vary depending on wind conditions, air traffic, and the specific aircraft used.

For more information about these airports, visit the St Louis Regional Airport (ALN) and Denver International Airport (DEN) detail pages, or use our flight duration calculator to compare other routes.