Facts
Industry-Statistics
Average Speed of a Commercial Jet
800-900
km/h cruise speed
Most commercial jet aircraft cruise at speeds between 800 and 900 km/h, or roughly Mach 0.78 to 0.85.
Explanation
Cruising speed has remained largely unchanged since the 1960s because modern jet engines are optimized for fuel efficiency at these transonic speeds. Flying faster would increase fuel burn exponentially due to wave drag near Mach 1. The actual ground speed varies considerably based on wind conditions, with jet stream tailwinds sometimes pushing ground speeds above 1,200 km/h.
Source: Boeing / Airbus