Mach Number Calculator

About this calculator

This calculator finds the Mach number — the ratio of an object's speed to the local speed of sound — using M = v / a. Mach 1 is the speed of sound itself, so a Mach number above 1 means the object is traveling supersonically.

Aerospace engineering students use it to check homework on high-speed flight, and pilots and aviation enthusiasts use it to understand how fast an aircraft is really flying relative to the air around it, since the speed of sound itself changes with altitude and temperature. Enter the object's speed and the speed of sound to get the Mach number.