Air distance from Thimphu, Bhutan to Ulaanbaatar, Mongolia is 1679.5 Miles (2703 Kilometers / 1458.5 Nautical Miles).
3 hrs, 29 mins is the flight duration between Thimphu and Ulaanbaatar. This is the In-The-Air flight time. You should also add the taxi time, airport wait times and possible delays due to bad weather, etc. for the total flight duration time.