Distance From Denis Island Airport to Ulaanbaatar Chinggis Khaan International Airport, DEI - UBN Distance

The distance from Denis Island Airport (DEI) to Ulaanbaatar Chinggis Khaan International Airport (UBN) is 4707 miles or 7575 kilometers or 4088 nautical miles.

The distance shown below is direct flight distance between airports. Straight-line distance does not account for the surface between the two points. It is the distance a bird or airplane would travel between the two points when flying above the surface. The straight line distance is the direct route between two points, regardless of whether or not there are roads that connect them.

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How long does it take to travel from Denis Island ( Seychelles ) to Ulaanbaatar (Sergelen) ( Mongolia )?

A one-way nonstop (direct) flight between Denis Island and Ulaanbaatar (Sergelen) takes around 10 hours 49 minutes.

Estimated flight time from Denis Island Airport, Denis Island, Seychelles to Ulaanbaatar Chinggis Khaan International Airport, Ulaanbaatar (Sergelen), Mongolia is 10 hours 49 minutes under avarage conditions. Your actual flying time may vary depending on wind direction/speed or weather conditions. This calculation does not include the departure and landing times of the aircraft. In addition, it does not cover the person identity check, ticket check-in and baggage collection times at the airport.

Travel Distance Between the Airports • DEI - UBN

Kilometers		7575 km
Statute Miles		4707 miles
Nautical Miles		4088 nm
Avg. Time of Flight		10 hours 49 minutes

Denis Island Airport to Ulaanbaatar Chinggis Khaan International Airport Flight Route Map - DEI to UBN Flight Path

Location of Denis Island Airport & Ulaanbaatar Chinggis Khaan International Airport is given below.
Click the map to view Denis Island to Ulaanbaatar (Sergelen) nonstop flight path and travel direction.

Click to see flight route on Google Map between Denis Island, Seychelles and Ulaanbaatar (Sergelen), Mongolia. .

Nonstop flight route between Denis Island, Seychelles and Ulaanbaatar (Sergelen), Mongolia.

Time Difference Between the Airports • DEI - UBN

Time difference between Denis Island (Seychelles) and Ulaanbaatar (Sergelen) (Mongolia) is 4 Hours.
Ulaanbaatar (Sergelen) time is 4 Hours ahead of Denis Island.

Location	Local Time
Denis Island (Seychelles)	2026-03-15, 20:25:18 +04
Ulaanbaatar (Sergelen) (Mongolia)	2026-03-16, 00:25:18 +08

Why should you arrive 3 hours before international flight? Flyers who are traveling to an international destination should arrive at the airport earlier than domestic flyers. This is because international flights can have additional check-in requirements, like passport verification, that need to be completed before you receive your boarding pass.

Origin

Denis Island Airport (DEI / FSSD) Denis Island, Seychelles

Destination

Ulaanbaatar Chinggis Khaan International Airport (UBN / ZMCK) Ulaanbaatar (Sergelen), Mongolia