Enter the value in mach (speeds of sound) to get the conversion into knots:

The Mach number is a dimensionless number expressing the ratio of an object's speed to the speed of sound. Thus, one goes at Mach 1 when moving at the speed of sound, at Mach 2 when going twice as fast, etc. The knot is a unit of speed used in maritime and aeronautical fields, expressing the number of nautical miles per hour, or about 1852 meters per hour.