Mach 2 is twice the speed of sound. At sea level under standard atmospheric conditions, Mach 2 equals approximately 1,534 miles per hour (about 2,468 kilometers per hour). This means an object or aircraft traveling at Mach 2 is moving at double the velocity of sound in air, which is roughly 767 mph at sea level. Mach 2 is significantly faster than a typical commercial jet and can reduce long-distance flight times drastically compared to subsonic speeds.