Mach 10 is roughly eight times the speed of a typical airliner: about 7,700 miles per hour. At standard conditions near sea level, Mach 1 (the speed of sound) is about 760–770 mph, so Mach 10 works out to around 7,600–7,700 mph (often quoted as approximately 7,680 mph in popular sources). This is why Mach 10 is classed as hypersonic —it’s ten times the speed of sound and far beyond normal aircraft speeds.