Why Do Planes Typically Fly at 35,000 Feet?
The air traffic control permission and the aircraft’s model determine the altitude a plane can reach. The higher a flight goes, the less fuel it consumes.

Cruising altitudes normally range from 30,000 feet to 40,000 feet. Although a plane may cruise at a higher level, this does not always happen during every flight. Depending on the weather, air traffic control might give another order, or the plane’s weight may limit it.